advice please overheating

[t5tart]

ok have a problem with a n/a 2.0 20v 850

fill her up with water she will run fine tickover
take her for a run and she will boil up
tried bleeding the system got rid of all the air ran fine for ages then spat all the water out again
steam leaking from around the expansion cap

thought head gasket no mayonaise anywhere water or oil

took out the t'stat thought it may have failed shut problem seems to have got worse

please dont tell me its head gasket cause i'm not listening

seems to be drawing air from somewhere but no visible sign of a leak

im confused



oh and hi again everyone

[iGGy]

Is it using the old grey colour cap or newer green one?

[t5tart]

Is it using the old grey colour cap or newer green one?

the newer green one replaced it a while ago
but took the old grey one off the t5 and still did the same

[BlackBeast]

Do you actually have coolant in the system, not just water? Is the fan coming on at all?

[t5tart]

Do you actually have coolant in the system, not just water? Is the fan coming on at all?


yes put coolant in ... and yes the fan is cutting in

its got e scratching my head

only think i can think of is a crack in a sleve or head

but have been pondering a blockage in the rad or somewhere like that causing a back pressure and airlock

[BlackBeast]

ok, can the heaters inside the car blow hot air?

[t5tart]

yes heaters blow hot

[JUDGENINJA]

do you have the fast and slow fan working..?

[t5tart]

fast and slow fan ???
which fan are we talking here?

[JUDGENINJA]

one fan.... it has a slow setting then a fast setting kicks in... big red wires goin to the fan I bridged the fast on so i've got a switch inside the car for those hot racing days

[t5tart]

one fan.... it has a slow setting then a fast setting kicks in... big red wires goin to the fan I bridged the fast on so i've got a switch inside the car for those hot racing days


ah i didnt know it was dual speed lol

not sure if its different on the n/a models but ill take a look
might be worth jumping it to high speed permanently instead of bothering with low sped
i wasn't really paying attention to that

ill pay more attention next time its running

[t5tart]

looking at the wiring diagram it has a green and a red i take it the green is slow and the red fast ??

[JUDGENINJA]

i've just been out to the car to check.
Yep green and red.
I've run a swtich to the Red wrie which is the fast fan...

[t5tart]

ummm might be worth a shot
but that is not going to solve the underlying problem really
as its boiling up quite bad


anyone know any signs to confirm a crack in the head etc
apart from a leak down test

whats confusing me also ids the system is pressurising
i thought if it were a cracked head it would not pressurise???

[MattB]

ah i didnt know it was dual speed lol
Neither did I!!!
I'm sure mine only runs at one speed??
(Sorry to hijack your thread t5tart. I'd love to help with your problem, but its got me baffled too!)

[iGGy]

Did you reverse flush the radiator? Might be worth checking the flow through the rad.

[t5tart]

Did you reverse flush the radiator? Might be worth checking the flow through the rad.

whats a reverse flush ??

god i'm thick sometimes

[t5tart]

no one any more thoughts ?

[blackbooty]

i know youve said "dont talk about head gaskets" but.......

i once said that during similar probs on a diesle astra mate.
turned out the combustion space (in the head)had been compramised and it was actually blowing gasses into the cooling galleries(water) and then causing boil over. no mayo, no oil/water mix.....

i know diesels work at much higher pressures, but it is a possibility.

only way to 100% eliminate head gasket prob is to do a sniffer test bud.

[blackbooty]

water pump probs ???
they have a seal that could be naff, alowing air to be sucked in .
no flow??
remove the relevent hose and start her, water should gush not trickle .

[t5tart]

ah thats a good one never thought of that
ill have to get to the car and have a look tonight see if the water is moving round right
I take it it does not matter which hose is taken off??
so long as the water is gushing out ?

[t5tart]

ok der me
whats a sniffer test ?

[blackbooty]

sniffer test is a kit you can buy that containes chemicals that when it is mixed with combustion gasses turnes a diff colour, you put some in a pippet, draw fumes from inside the expansion tank and if exaust gasses are preasent it will change colour thus telling you the head gasket is blowing without having to remove the head and examine the gasket/head.

one pipe will suck water, one will pump(i presume, ive not had a water pump off on an 850), ill find out which one for you if you cant sus it yourself mate.

[t5tart]

coolant pump does not appear to have pipes is in the side of the block bnottom of the timing belt

[blackbooty]

just had a look in haynes for you and theres no direct pipe to these pumps,so youll have to fill the system,get it up to temp to make sure the therm is open, and then remove a hose while engine is off (one at the top of the system, so you dont loose all the coolant to gravity) and turn the engine over.
you should then get the coolant pumping out, so dont point at yourself or engine of corse.

worth a try cos its an easy check mate.

changing the water pump looks a bit of a mare cos timing chain/belt has to come off.

hope its something much easier for you bud.

[t5tart]

just had a look in haynes for you and theres no direct pipe to these pumps,so youll have to fill the system,get it up to temp to make sure the therm is open, and then remove a hose while engine is off (one at the top of the system, so you dont loose all the coolant to gravity) and turn the engine over.
you should then get the coolant pumping out, so dont point at yourself or engine of corse.

worth a try cos its an easy check mate.

changing the water pump looks a bit of a mare cos timing chain/belt has to come off.

hope its something much easier for you bud.

yer got the haynes book here myself timing belts scare the hell outta me sure they are simple enough but i'm petrified of totally knackering it
hahahaha

no therm in it at min so should be dead easy to take of the therm hose and turn it over :B_steerin

[t5tart]

sniffer test is a kit you can buy that containes chemicals that when it is mixed with combustion gasses turnes a diff colour, you put some in a pippet, draw fumes from inside the expansion tank and if exaust gasses are preasent it will change colour thus telling you the head gasket is blowing without having to remove the head and examine the gasket/head.

one pipe will suck water, one will pump(i presume, ive not had a water pump off on an 850), ill find out which one for you if you cant sus it yourself mate.


thanks for that wonder if i can get one

any idears if they are pricey

[t5owner]

whats a reverse flush ??

god i'm thick sometimes

Reverse flush

Remove bottom radiator hose and put hose pipe in make sure water doesn`t gush back out so seal the pipe in place somehow

Switch on water and it will flow in reverse through the system and hopefully remove any crap / clag thats in there and flush it out via the disconected radiator hose

You should allow at least 15 mins for this to wash out the coolant and anything else

Cheers

stuart

[t5tart]

Reverse flush

Remove bottom radiator hose and put hose pipe in make sure water doesn`t gush back out so seal the pipe in place somehow

Switch on water and it will flow in reverse through the system and hopefully remove any crap / clag thats in there and flush it out via the disconected radiator hose

You should allow at least 15 mins for this to wash out the coolant and anything else

Cheers

stuart

thanks for that
might have to give that a go too although on the rad side shouldnt be too bad as the rad is fairly new

[blackbooty]

they can be bought mate but i have no idea where from or how much im affraid.

put a new thread out asking about availability and cost and im sure the many members that own/work in garages will be able to advise.

good luck.

[T5ER]

sorry to dissapoint mate but that deffo sounds like head gasket problems i have a had gasket tester and fluid to see if there are any problems with that side of it and it does not lie

[t5tart]

well drained and flushed the coolant this evening
refilled it with 50/50 coolant and deionised water

got loads of air out seemed to settle at about 7 ltrs...which i believe is the coolant capacity

now silly me did this without reading the haynes manual fully and it says to use only volvo coolant

can someone tell me if the volvo coolant is etter at dispersing heat or has a higher boiling point or something ?

[t5tart]

sorry to dissapoint mate but that deffo sounds like head gasket problems i have a had gasket tester and fluid to see if there are any problems with that side of it and it does not lie

great
trouble is i am loaning the car to a mate and he has it so a bit difficult to get to you even though you not that far ... esp with it apparently overheating
ill see what happens with this drain and flush over the next couple of days
and see if it has solved the problem

[Baj]

Volvo coolant gives Volvo more money, nothing more afaik.

Any modern Ethylene Glycol based coolant should work.

Saying that, mine goes to operational temperature very quickly and then stays there regardless. I am happy it has no overheating issues but is it normal to reach running temp in under a couple of minutes? I am used to being halfway to work before the heating kicked in.

[t5tart]

wooohooo just got a phone call off my mate who has just managed to get home without it boiling over
so we may well be making progress here

[blackbooty]

well drained and flushed the coolant this evening
refilled it with 50/50 coolant and deionised water

got loads of air out seemed to settle at about 7 ltrs...which i believe is the coolant capacity

now silly me did this without reading the haynes manual fully and it says to use only volvo coolant

can someone tell me if the volvo coolant is etter at dispersing heat or has a higher boiling point or something ?

nahhh dude,volvo want u to use their stuff cos its pricey !!!

i wouldnt keep giving it 50/50 till i sorted the prob mate, gonna get expensive, basically run it on water till you find out whats up, if it keeps dumping/boiling it out, your throwing dollar away.

anti freeze/summer coolant is a must if alls ok, if its throwing it out and your having to drain/refill all the while.... why bother !!!

really want to be sorting an overheating prob before its leant to a mate.

many engines have died cos of overheating, next to no oil....
coolant loss is the next biggest worry !

be careful matey.

[t5tart]

yer well it was a spare car rotting on the drive
the coolant aids cooling think the boiling up was due to too little coolant was running on almost pure water and probably an air lock

however we will now see wanted to drain it and fill it from scratch with everything right

oh and the maye is totally paranoid about it overheating he is a good bloke
and at the end of the day the car was laid up and would probably have been scrapped anyhow

[T5SLAVE]

I take it you have checked that your expansion tank cap is functioning correctly?

I say this cos I remember years ago running around in a Mk2 Golf GTI with an overheating problem that everyone and thier dog was convinced was headgasket (me included!) after about 3 weeks of sheer frustration I was just about to get the lump seen to when a mate o mine spotted the fact that the rubber 'o' ring seal in the exp tank cap was fubar'd...popped off to Halfrauds new 'o' ring bought, ftted and hey presto overheating gone:biggrin:

Probably just a VW thing tho:confused: Sold the car straight after n bought another RST cos it annoyed me so much:cuckoo: :)

[LeeT5]

:shockedbi :yikes:
just had a look in haynes for you and theres no direct pipe to these pumps,so youll have to fill the system,get it up to temp to make sure the therm is open, and then remove a hose while engine is off (one at the top of the system, so you dont loose all the coolant to gravity) and turn the engine over.
you should then get the coolant pumping out, so dont point at yourself or engine of corse.

worth a try cos its an easy check mate.

hope its something much easier for you bud.

:eye-poppi :doh: :yikes: If you want to burn yourself crack on, but i would advise against doing the above!! (sorry blackbooty but your methods are dam right dangerous). Blackbooty you are right about the sniffer test but to back it up you need to first carry out a pressure test. To clarify, a sniffer test will not always detect carbon monoxide in the header tank because it depends where the head gasket is leaking, if at all it is the headgasket. Do a pressure test on both the cooling system and the header tank cap. If both successful then just replace the thermostat (dont bother trying to check it they are too cheap to bother mucking about, just replace). Turn heater controls to hot and bleed system, revving the engine now and again to purge air from the water pump. Once up to max mark (or cold line) you can then let the system and engine get up to operating temp. Whilst this is happening you can easily check the pump without removing hoses (and risk of getting scalded) but simply watching the return flow to the header tank. It should gush in when you rev, Simple!!
Once the system at operating temp both the top and bottom hoses will be hot. Temp guage should not go above midway and shortly after the fan should cut in. Make sure the aircon (if fitted) is switched 'off' otherwise the fan will be constanty on from the word go. Once the fan cycles on then off note the temp. Should be still about midway, slightly above. All above is done with the cap 'OFF'
If you now drive the car (cap on) the car should not overheat or boil over, if it does then you have a problem ie partially blocked rad or headgasket slighty leaking and pressureising the coolant system.

I go out to overheating cars everyday so i can defend everything i have said. Without the proper equipment you cannot acurately diagnose a headgasket problem....either invest or call out the AA / RAC. We carry all the above equipment to test properly.:)

To finish i would say from experience that your problem lies firstly with the thermostat (common fault on 850 entire range) then headgasket! (rare). Waterpump is unlikely although possible. Please remember that not having a 50/50 mix will lower your boiling point by as much as 5 degrees Celsius and a leaking cap by as much as 8 degrees.

As an AA patrol we can also see what the temperature is that the ecu is seeing via the temp switch using the OBD socket and a laptop!!! Worth seeing believe me.
Goodluck dude.

[blackbooty]

neat H2o will not cause an engine to overheat mate, fact.

not good if left in there permanantly tho.

just trying to save you wasting £££££

[LeeT5]

neat H2o will not cause an engine to overheat mate, fact.

not good if left in there permanantly tho.

just trying to save you wasting £££££

Correct, note i never said it would! But if you had a leaking cap and neat water in your system then i also garantee the car would overheat on a run, probably not at idle in the driveway but drive the car and it will overheat.

Water boils at about 92 degrees C, atmospheric pressure sea level. So a leaking cap will not pressure up the system and thus the engine will boil over cos the engine will get hotter than 82 degrees (thermostat opening) on a run, but probably not at idle. Add a working cap, boiling point raised to approx 97 degrees, add 50/50 mix glycol and it will go up a further 8 degrees thus boiling point is now approx 105 degrees. Now the coolant cannot boil and further increase the pressure and cause it to boil over!!

Wasting pounds is spending money on headgasket work and replacing associated parts when the fault has not even been diagnosed properly in the first place. Doing the job properly or investing in the proper kit will save expensive cooling repairs down the line oh yeah and a lot of stress!!

Ps For those out there (hopefully no one here) that doesnt bother with coolant then you are massively degrading the internals of your engine and will almost certainly cause premature failure of the water pump because glycol is a lubricant for the waterpump and also has anti corrosion propertys to protect the engine. Nuff said!

[blackbooty]

Lee, sounds like text from a manual to me mate.

read all posts and its clear that i warned against being in close proximity to hot water.....

the sniffer test i mentioned is regarding exhaust gasses being blown into the cooling system... nothing else, the sniffer test is ONLY used to detect exhaust gasses in the cooling system.

previouse posts had already determined that no oil/water mix had been discovered and the therm had been checked out.

if matey had the cash to put it into a garage or join the AA he would have done so and not bothered to post his probs.

its plain to see you know youir stuff but please realise not everyone is a retard like you meet on the side of the road.

read all posts, and then your reply mate, youve gone slightly over the top.

wayne

[blackbooty]

were both tryin to help someone mate, lets not bitch.

last thing id suggest is a dangerouse move !!!

read my posts and youll agree.

xxx lee.

[LeeT5]

Lee, sounds like text from a manual to me mate.


LOL......... Nah m8, straight from the horses mouth. From a manual it may well be but that manual is in my head. I do this daily so i know what im talking about (not saying you dont of course).

BTW you did say to 'remove a hose when the engine was hot'...:nono:
Safety first and all that..

Not meaning to blow my own trumpet but i am an AA patrol, 16 years in the trade and only last week did a cooling refresher update course. The AA way is the only way because it is the industry recognised standard way of testing cooling systems. So if you dont use correct equipment, you are guessing. A full system function test on a cooling system takes about 1 hour. We do it at the roadside, any faults WILL manifest themselves in less than that and so the appropiate action can be taken ie fix the car or tow it to a garage depending on severity of the fault.

Ps i'm not bitching i assure you - :biggrin:

[BlackBeast]

LeeT5, whats your thoughts on these coolants that you dont need to add water to, specifcally the Motul one?

[LeeT5]

LeeT5, whats your thoughts on these coolants that you dont need to add water to, specifcally the Motul one?

Honestly?? Never heard of it. As far as i know 'Motul' is a company name like 'Castrol or Shell'. As for not adding water??? are you sure its not already premixed?

[Baj]

Dont some racing people run 100% coolant.


There is enough decent oil in this engine isnt there?

[LeeT5]

Dont some racing people run 100% coolant.


There is enough decent oil in this engine isnt there?

No, because running neat coolant is the same as running neat water. It will not raise the boiling point.

[blackbooty]

hmmmm

[t5tart]

Lee, sounds like text from a manual to me mate.

read all posts and its clear that i warned against being in close proximity to hot water.....

the sniffer test i mentioned is regarding exhaust gasses being blown into the cooling system... nothing else, the sniffer test is ONLY used to detect exhaust gasses in the cooling system.

previouse posts had already determined that no oil/water mix had been discovered and the therm had been checked out.

if matey had the cash to put it into a garage or join the AA he would have done so and not bothered to post his probs.

its plain to see you know youir stuff but please realise not everyone is a retard like you meet on the side of the road.

read all posts, and then your reply mate, youve gone slightly over the top.

wayne

lol not enuff money
sorry chap you have that wrong but it is an old car that is purley for a loan for afew weeks

i have ful aa with roadside homestart and relay so no problems there
but dont see the point in using it if i can fix it myself i could take a patrol off the road that could be attending to a young woman with a kid who is sranded with a puncture

all i did was ask some advice as i was running out of ideas

[t5tart]

Dont some racing people run 100% coolant.


There is enough decent oil in this engine isnt there?


plenty of oil matey although it is due a change

[abdul]

i had a volvo 850 had the same problem changed head gaskets turned out to be the radiator was blocked

[t5tart]

seems the rad was blocked flushed it and it seems fine fingers crossed

[LeeT5]

lol not enuff money

i have ful aa with roadside homestart and relay so no problems there
but dont see the point in using it if i can fix it myself i could take a patrol off the road that could be attending to a young woman with a kid who is sranded with a puncture

all i did was ask some advice as i was running out of ideas

Dont take this the wrong way but if you can fix it youself why are you asking so many questions? sounds like your not really sure m8 what your doing. The reason i said about the AA was because you would know what the fault is in less than an hour and dont worry about taking a patrol off the road cos there are always more patrols than jobs on the road. just trying to help!

[t5tart]

Dont take this the wrong way but if you can fix it youself why are you asking so many questions? sounds like your not really sure m8 what your doing. The reason i said about the AA was because you would know what the fault is in less than an hour and dont worry about taking a patrol off the road cos there are always more patrols than jobs on the road. just trying to help!

isnt that what this forum is for to share knowledge??
I like to solve things myself I have one of those brains
I like to solve puzzles

however i never thought of a blocked rad

[t5tart]

Thanks for all the help guys

seems the problem is fixed

£4.99 bottle od slick 50 rad flush through the top hose run it for 10 mins
proper 50/50 mix of coolant and de-ionised water
and she is so far running sweet

seems the rad flush was the key .... at least is saved me a head strip

[t5tart]

Thanks for all the help guys

seems the problem is fixed

£4.99 bottle od slick 50 rad flush through the top hose run it for 10 mins
proper 50/50 mix of coolant and de-ionised water
and she is so far running sweet

seems the rad flush was the key .... at least is saved me a head strip

[LeeT5]

isnt that what this forum is for to share knowledge??
I like to solve things myself I have one of those brains
I like to solve puzzles

however i never thought of a blocked rad

Guess you werent in a rush to get your car fixed then (waiting for ppl to reply to Qs) anyway, well done for finding the fault, i might add at this point that all AA patrols carry laser temperature probes, so your blocked rad would have been found in minutes. At least it's sorted now.

[t5tart]

ah but thats the easy way out
and you are right was in no real hurry

would rater keep my aa call outs for real emergencies

as i said b4 the car was going on loan to a mate and his short hops to work were not enough to overheat it
but on the test run we did it did overheat so got my head scratching

[t5tart]

Happy to report that after 4 years stood on a drive very much unloved and unstarted
she started first turn of the key
needed one tyre where some vandal had punctured it
and an alternator (thanks salvo)
and the rad flushig and reflling with coolant

so £80 and she is back running sewwt
a testament to volvo's i think that she is in such good shape after beeing stood so long

[M44K TS]

sorry to pull this thread back up, but how exactly do you flush the radiator? Could there be an air lock as the top hose coming from the rad seems to be under alot of pressure on mine and sems happy to empty the header tank when the cap is unscrewed.

Also is it normal for when the coolant is topped up to 'max' then with the cap unscrewed, slowly rises.

[JUDGENINJA]

I'm not sure if there is a drain plug for a Volvo but the easiest way would be to just pull the bottom hose off and let all the water drain out. Then with a Hose run water through the system until the water coming out is clear. You could run the car at the same time but you've got to be really carefull, so don't if you have any doubts... then re-attach the lower hose and fill with anti-freeze and water mix..... job done....

it's very messy so I'd be tempted to find the nearest drain outside your house to place your car over to do this job...

[t5tart]

bottle of slick 50 rad flush through the top hose by the thermo housing
run for 10 mins or so

take off the bottom hose by the rad
refil with water and run for a further 10 mins or so
re drain system

then fill with 50/50 mix of coolant and de ionised water

shouldnt really get any air locks if its poured in slowly with the engine running as its poured ( very important) as you want the water moving as much as poss round the block with an ally block

once it tops up to the max let her uun or take her fro a run till proper operating temp

leave overnight to cool and then top up to the max line again should be job done
just keep an eye on the level over the next week or so cause some air may come out but should not be alot

[M44K TS]

cool, job for the weekend then

[M44K TS]

well, it's been flushed 3 times, and new coolant in, took it for a quick drive and all seems well, touch wood hehehe

[t5tart]

great