2000 Volvo C70 T5 Engine Stutter

[willsalisbury1984]

Hi all,

This is my first post in the forum and have just joined today so thank you all in advance for your help.

I am the proud owner of a 2000 Volvo C70 T5 in turquoise pearl. I have always heard great things about the T5 engine especially and used to work with a guy who used to service the Police T5's.

I was lucky enough to pick one up a week ago very cheaply with 234 000 on the clock. It has full Volvo service history from 31 000 to 231 000 and all the stamps in the book and receipts to match. It seems to have been very well looked after. It had some superficial damage but have just spent the last week sanding down, filling, priming and painting all blemishes.

The problem I have is that yesterday I started the car and the ETS light was on for maybe 5 minutes. I turned the engine off and back on and it disappeared. I thought nothing of it but then on the way to work this morning:

In traffic between 5-15 miles an hour acceleration is fine but the moment I take my foot off the accelerator and brake the revs will dive to 500rpm and then back up to 900/1000. The car almost judders/sounds like it wants to stall for a split second before going back to its normal idle.

I will accelerate again and revs are normal and car feels fine but then when breaking in traffic or stop starting then the moment foot is off accelerator or on break then there is this almost juddering and constant dip in revs.

I thought it may be a transmission issue but this morning I left the car in 1 (automatic) and did exactly the same where I accelerated and then breaked but the car did exactly the same thing again, so I am assuming that the juddering and dip in revs is not caused by the automatic box changing up to 2nd and then diving back down to 1st as I left the car in 1st.

The only way I can really describe the issue is as though you were driving a manual and changed into second in a diesel and then were lazy in slow traffic and didn't put foot on clutch and just before car stalls you get the judder, dip in revs and the almost lurch forwards.

Nothing seems to have been lost in terms of power or acceleration or response but its just a very weird sensation as momentarily I almost feel like the car will stall. As a test I even accelerated, knocked the car into neutral and then hit the break in slow traffic and again I had the dip in revs and judder.

The last thing to say is that this seems to only happen when the car is warm. I don't think I have experienced this at all in the first part of my journey.

I have read lots on the internet about the ETS light, hooking my car up to a computer, the MAF etc but essentially what I would like any help or advice with would be if:

Anyone has experienced this before?

Best course of action?

Am I ok to still be driving the car?

Is this a problem I can look into or do I need to take to a garage?

I really do not want to go out and buy a 'Bosch MAF, disconnect battery' as one piece of advice has suggested if this will not solve the problem, especially when Bosch MAF's are about 5 times the price of ones on ebay.

I apologise for any incoherence in the email and the long winded nature and really do thank everyone so very much in advance for all help.


Thanks again,

Will
2000 Volvo C70 T5, Turquoise

[multiskilled]

Hi ive been having the same trouble never had the ets light on but have tried cleaning , changing various parts (not maf yet) and checking for split hosesand never realy sorted it. But have now found a sensor which is on the pipe attatched to the etm, if i follow these wires of the sensor to where they join a bunch of shrouded wires and move them about it nearly stalls so am going to have a look friday night will let u no if its sorted it

[Wobbly Dave]

I've owned a c70 t5 with the same engine as yours for a wee while now. Personally I would be looking to get the codes read. You can get cheap wireless ODB2 interface, that plugs into the arm rest for a tenner. Then if you have an android phone download something like TORQUE, & read the codes. Or alternatively take it to garage & get them to do it.

Just going off what you said - I would be also tempted to take the ETM off & clean it, as a starting point. You may have a failing ETM which is a spring loaded butterfly valve, controlling the throttle. Unit may fail regardless (its a design fault with the magneti marellii unit). There was a class action suit in the US over the units back in the noughties. However cleaning it is relatively easy to do. Or you can just search for a 2nd hand unit or there are plenty of reconditioning firms out there. You can get the updated MM units which do not face the same issue.

https://www.youtube.com/watch?v=8Zaxtm-hdyo

http://volvodiagnostic.com/shop/index.php?id_product=18&controller=product
http://www.vexedvolvo.org/

http://ourvolvo.com/etm-problem-1999-volvo-v70/

there's lots of evidence & issues out there. Usually symptoms are characteristed by an uneven engine idle speed.

BTW Cheap MAFs on ebay are worthless in my experience. If you unplug them the ME7 system is designed to go to a default setting - please do not confuse this with normal running.

[Wobbly Dave]

Hi ive been having the same trouble never had the ets light on but have tried cleaning , changing various parts (not maf yet) and checking for split hosesand never realy sorted it. But have now found a sensor which is on the pipe attatched to the etm, if i follow these wires of the sensor to where they join a bunch of shrouded wires and move them about it nearly stalls so am going to have a look friday night will let u no if its sorted it

Those sensors are the IAT & MAP sensors (Intake Air Temp) & (Manifold Air Pressure) - I have spares of these if anyone wants them.

[willsalisbury1984]

hi all,

Thanks so much for all great answers. An absolute legend brought a DiCE around to my house I had some codes read and was wondering if anyone knew any of these and any potential ways to fix them? The guy with the DiCE saw the idle problem and stutter but the only codes were the ones below so could this be a pure turbo problem?

The first one was:

ECM-1600- Boost pressure sensor signal too low.

ECM-170f-Boost pressure sensor faulty signal

ECM-201a-thermostat faulty signal

I think there may be a turbo issue as when the DiCE was hooked up then on the live communication it didn't look like the turbo was registering.

Any ever come across these issues?

Would it be recommended firstly to check all hoses?

Then anything else after this?

Thank you all so much again,

Will

Also Wobbly Dave-were I to need those sensors then what's best way of getting them from you.

Thanks again,

[Wobbly Dave]

Just drop me some details & I will sort them out for you. I also have a t-stat sensor if you need one.

[willsalisbury1984]

Just drop me some details & I will sort them out for you. I also have a t-stat sensor if you need one.

Hi Dave,

Sorry for 3rd post. Just looked again and in short terms it's only MAP I need.

If you PM me your details I will send you some money.

Apparently it's a 5 minute job?

Will

[Wobbly Dave]

Yeah the MAP sensor is held on with 2 plastic clips on the main I/C pipe. Just unplug it & prize it out of the saddle. The connector sticks out at 45 degrees relative to the pipe.

I pinched this image out of a google search.


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