C70 T5 Boost Problem.

[Alex.]

Hi Guys,

I have a 1999 C70 T5, with the ME7 engine and a distinct lack of performance.
Driving down the motorway there is not as much oomph as I remember when acclerating to overtake, nor is the full bore acceleration as quick as it should be.

It feels very similar to my previous car, a V40 T4, which also lacked performance and was restored with a new turbo.

During some previous work, I had removed the heatshields around the turbo and not put them back. So I can hear the wastegate chirping on gearchanges, this does not seem to have changed.

To see what this turbo is doing, I purchased a bluetooth OBD2 dongle and installed the Torque app on my phone. This has shown that the turbo is only boosting to 6psi.

Today I changed the air filter, just in case that was blocked and restricting air flow. No change to performance or boost level.

The car has done 140k miles, 45k of those with me and it might still be the original turbo unit.
What other parts surrounding the turbo itself could be at fault and how can I test them?

Please help, I'd rather not splash out on a new turbo only to find it is some of the control parts next to it!

Alex.

[Dream3r]

The torque boost calculation is a guestimate based on maf readings, so you can't rely on it.

First of all get the codes read by VIDA and check for any leaks, the early ME7 cars don't have much diagnostics for air leaks so inspect everything.

My first instinct is to replace the TCV valve, but best check for leaks and wastegate operation before throwing ££ around.

[LeeT5]

What he said ^^^^

1. Codes.
2. Air leak/Boost leak.
3. Get your car smoke leak tested.

[Doingitsideways]

As above.

I'd also suggest BCV/TCV, bound to be past its best by now.

Get the codes read properly though

[Wobbly Dave]

Torque is cheap - (and disappointing).

[Alex.]

All of the pipes are fairly new, replaced 2 years ago when I replaced the exhaust valve on cylinder no 1. I will be checking them anyway, especially the clamps.

I've just found which part is the TCV, shouldn't be too hard to replace. Anyone got a spare they would part with?

How would I go about testing the wastegate?

Alex.

[LeeT5]

All of the pipes are fairly new, replaced 2 years ago when I replaced the exhaust valve on cylinder no 1. I will be checking them anyway, especially the clamps.

I've just found which part is the TCV, shouldn't be too hard to replace. Anyone got a spare they would part with?

How would I go about testing the wastegate?

Alex.

You will require a Mityvac!

Checking clamps is one thing, but you can't physically check that they aren't leaking unless you have a smoke leak test done.
I thought my car was leak free and all clamps done up tight, yet the smoke leak test found 2 leaks and one of them was massive! The Mityvac found the last.

Mityvacs cost about £80 and a smoke leak test is an hours labour at any Volvo dealer.

[Alex.]

You will require a Mityvac!

Checking clamps is one thing, but you can't physically check that they aren't leaking unless you have a smoke leak test done.
I thought my car was leak free and all clamps done up tight, yet the smoke leak test found 2 leaks and one of them was massive! The Mityvac found the last.

Mityvacs cost about £80 and a smoke leak test is an hours labour at any Volvo dealer.

An hours labour at the local Volvo dealer was £95+VAT 4 years ago! Is the smoke leak test on a T5 something only a main dealer can do, or will a local independent have the appropriate kit?

Alex.

[Dream3r]

MRG at Chippenham did mine waaay back with a smoke machine, they made a very good job of finding a leak.

Now I do my own leak finding, it's fun......sometimes :)

Simon Chui @ MRG is the service manager

[960kg]

All of the pipes are fairly new, replaced 2 years ago when I replaced the exhaust valve on cylinder no 1. I will be checking them anyway, especially the clamps.

I've just found which part is the TCV, shouldn't be too hard to replace. Anyone got a spare they would part with?

How would I go about testing the wastegate?

Alex.

Hello Alex, Keith here how is Rainham?...

Glad you got the valves sorted ......haven`t heard of you for a couple of years, you must have found reliabilty!...Lol

I would start first with the thing that doesn`t cost anything and that is the simplest way to test the TCV is to remove a hose from it and just go up the road.

Be careful as it will boost like crazy on max. boost if no other faults...if no change then you will have to look elswhere like making sure the actuator is not rattling and adjust ok...

Good Luck
Keith

[Alex.]

MRG at Chippenham did mine waaay back with a smoke machine, they made a very good job of finding a leak.

Now I do my own leak finding, it's fun......sometimes :)

Simon Chui @ MRG is the service manager

Chippenham is a little far, be cheaper to go to the dealer!
I'll look for someone closer.

Alex.

[Alex.]

Hello Alex, Keith here how is Rainham?...

Glad you got the valves sorted ......haven`t heard of you for a couple of years, you must have found reliabilty!...Lol

I would start first with the thing that doesn`t cost anything and that is the simplest way to test the TCV is to remove a hose from it and just go up the road.

Be careful as it will boost like crazy on max. boost if no other faults...if no change then you will have to look elswhere like making sure the actuator is not rattling and adjust ok...

Good Luck
Keith

Hi Keith,

Rainham is doing fine, even getting a third platform at the railway station!

The head rebuild went smoother than I could have hoped, still running sweet 2 years and well over 20k miles later. Only little niggles going wrong, like a new radiator last year on the way home from Wales. She doesn't like leaving Wales, not that I can blame her I'd move back tomorrow given the opportunity!

I'll try removing a pipe, then pop down to BD Engineering and have a chat.
will any pipe do, or is there a specific one?

Alex.

[Alex.]

Just a quick update, finally got a chance to remove a pipe from the TCV.
As a control, I re-took the boost readings with torque before changing anything and she still only boosts to 6psi.
Took the top pipe off the TCV and she boosted to 10psi!

Looks like I'm in the market for a new valve...

Alex.

[LeeT5]

Which pipe did you remove?

[Alex.]

Which pipe did you remove?

The one on top, easiest to get to in Asda car park!
I wasn't sure which to remove, so just removed one from the turbo. Reasoning being that if any one pipe was not attached then it could not work as expected.

Alex.

[Alex.]

As a replacement part is either £20-£30 used on ebay, or £57 genuine brand spanking new, I've ordered a new one for tomorrow.

At least I should have full power for the weekend away at the in-laws!

Alex.

[kmb]

Please could you provide links to the part on Ebay (and/or Volvo) - I had no luck finding one for my 96' 850 T5 (I wanted to change as a service item).

Hope it fixes your problem :)

[Alex.]

Please could you provide links to the part on Ebay (and/or Volvo) - I had no luck finding one for my 96' 850 T5 (I wanted to change as a service item).

Hope it fixes your problem :)

I just looked at the part that is on there and searched ebay for the part number. Mine is 9155936.
Then I just phoned the local dealer and asked how much it was for the brand new genuine one.

Alex.