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Premature engine wear - low compression

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

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V70sorry
Posts: 7
Joined: 12 April 2006
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Premature engine wear - low compression

Post by V70sorry »

Anyone experienced serious engine compression problems? Having suffered through two bad ETM's now have seriously bad compression in cylinders 3,4,5. Only 75k mi (some signs even earlier) and obviously haven't missed an oil change and the engine appears to be shot!

My first Volvo is looking like my last after having thought I was going to be a life-long Volvo owner....

White850Turbo
Posts: 923
Joined: 11 April 2004
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Location: Plano, TX

Post by White850Turbo »

What kind of compression tester are you using? I hope it's the screw in type. Did you test it dry and wet?

I also find it hard to believe that you've gone through two ETM's in only 75k miles. It seems that most people don't have trouble w/ their first until around 90k+ miles.

What model year car is this? What type of driving is it used for? Any short trips?
-Sean

1995 850 Turbo (Extensively Modded)

1998 S70 T5 (Almost Stock)

V70sorry
Posts: 7
Joined: 12 April 2006
Year and Model:
Location:

Post by V70sorry »

It's a 2000. Driving initially was a long commute for the first 4 years but now is mostly very short trips with occassionaly long ones.

Did both wet and dry and both showed low. Is that indicative of rings or valves?

After some back and forth with the dealer they finally replaced the first ETM about 63k mi. I started having problems again and took it back about 75 kmi thinking I had a bad replacement part. They insisted the problem was not the ETM and it was getting fouled and needed a new fire trap. Also noted some signs of blow-by. Not believing (after they insisted the accel pedal simply needed to be replaced which of course did nothing) I took the car to my mechanic who after a few other fixes determined what he thought was a bad ETM and replaced it.

The hard lesson I think I've learned is that I should have troubleshot the blow-by then but wouldn't have made much difference. I'm wondering if the blow-by is indeed fouling the ETM and the real source of some of these problems.

White850Turbo
Posts: 923
Joined: 11 April 2004
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Location: Plano, TX

Post by White850Turbo »

Your car doesn't have a flame trap; dealer is trying to wiggle their way out of replacing the ETM again. I certainly think it is believable for the ETM to be ruined by excessive blowby. The PCV system putting all those carbon/oil deposits all over it can't be good for it.

Anyways, yeah, if it was low wet and dry, then rings are not the problem. These cars don't do well with short trips where they are not allowed to warm up. I've certainly heard on plenty occasions, of cars that are used for mostly short trips, burning valves. That'd be my bet. It'd be cheapest to just throw a junkyard head on there, though you could always look around and see how much a machine shop would charge for a rebuild. If you're a reasonably competent weekend mechanic, pulling a head on these cars is not very difficult.
-Sean

1995 850 Turbo (Extensively Modded)

1998 S70 T5 (Almost Stock)

V70sorry
Posts: 7
Joined: 12 April 2006
Year and Model:
Location:

Post by V70sorry »

Is there anyway to be certain it is the valves?
And no flame trap?? Is there something that serves the same purpose on this model I should be paying attention to?

You've got me thinking now. I was starting to look around for a used engine but a head wouldn't be that bad. I would call myself a marginally competent weekend mechanic so this would be on the edge for me but between a neighbor who does a lot on his Volvo's and myself it might be doable.

Reading through a number of the other pages the last few days I've realized how naive I was about maintaining this car - should have been worrying about oil sludge and clogs, and other preventative maintenance. I should have been doing the oil etc myself rather than the corner oil change place. I should be beaten with a shovel but instead I get to learn this hard way I guess...

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