Car was running good until vibration during acceleration. Had it checked at a non volvo shop and they found #2 cylinder with no compression. Dis all the tests but compression remained at o > All other cylinders had 135 psi compression. Looks like it needs a valve job. BTW there is 267000km on the clock but the car is in very good shape.
Would you fix it and what do you think it would cost?

 

I would fix it, sounds like it needs a replacement motor. It only has 165,000 miles which is nothing for these cars, if properly maintained.

Here's the kicker, how long have you had the car? If the compression numbers are that bad what else has been neglected? Compression numbers should be 156 - 185 so those numbers are WAY low. My guess would be that someone skipped a LOT of oil changes. If they skipped oil changes, EVERYTHING ELSE was neglected. The good thing is that these cars were built very well. That's why it looks good. Maybe that's the only thing they did, keep it clean and fix what breaks.

Have the car checked out from bumper to bumper to find out what other problems are lurking to surface then make your decission. It is possible that you need a lot more maintenance that will cost you some good $$$.

Has the timing belt been replaced?
How old is the suspension?
When was the plugs last replaced?
Has the ETM been replaced?
Is the brake system due replacement?
Are the brake lines cracked?

I suggest you look at this situation as a CAR PURCHASE PROPOSAL. If someone came to you and offered you this car for $100, pay the $100 knowing that you needed a new motor and other things that are now pending? Look through the DIY Sticky section in the 850 section and check out the buyers guide. If you would take the car knowing it has a bad motor and other problems you or a mechanic finds, move forward. It may be time to cut bait and run.

 

Thanks for the reply. I have owned the car for 10 years. Switched to Mobil 1 synthetic 6 years ago and change the oil at 7-7500km. Car is well maintained. An interesting point, when the non Volvo tech removed the plug in the effected cylinder, the plug was broken in half where the porcelain met the steel body.
I spoke to 2 Volvo techs and they feel a valve job is what is in order but they have not seen the car. They also felt the compression was low but after the valve job it would most likely go back up to the acceptable range.
Everything else on the car has been well maintained. Only routine maintenance work needs to be done.

 

Thanks for your reply. What octane and type of fuel do you normally pump? Also, have you ever run fuel injector cleaner in the gas tank?

Having a broke spark plug, the car had to be missing? Did you have a cel and rough idle prior to loosing compression? When was the last time the plugs were replaced?

The compression being low across the board is NOT good. They can do what is called a leak-down test to see if your valves are leaking or your piston rings are worn. Seeing that you have been replacing oil every 4,600 miles with full synthetic oil is awsome, I'm really surprised to hear that you have compression issues, I'm stumped. Unless the compression issues are with dirty valves from running bad gas. I've been under the impression that running good quality full synthetic oil will help your motor last forever.

I really appreciate you sharing. Do figure out WHY your motor burnt a valve. You don't want to repair the motor and find yourself back in the same boat in 2 years from not fixing the source of the initial problem.

 

The car started to vibrate on acceleration 2 days before I took it to a tech. It was only on acceleration as far as I could tell. Other than that it ran well. I always run Sunoco Ultra 94(in Canada) or Ultra 93(in the US). There were never any other engine issues with this car other than burning some oil. I was told by Volvo service that this was normal with a high pressure turbo. I'm concerned by the lower compression in the other cylinders. After speaking with a Volvo tech he said that with 267000km and a high pressure(T5) turbo the other valves could be starting to wear and it wasn't long for a valve job. I bought the car 3 years old, 10 years ago and I really baby this car. The tech wasn't surprised and implied this happens more than you might think. My question is if I decide to have it repaired and have the head rebuilt, is do they replace the valves in the defective cylinder or all of them . I assume that with having the head rebuilt that they would replace all the valves etc.
The guy that found the issue and did the wet test etc had never worked on a Volvo T5 so I'm not to confident with what he is saying (good guy but no Volvo experience). I need to tow it 40 miles to a Volvo dealer and I don't want to be held ransom when I get it there.

 

Man, you don't have to baby these cars, just keep them serviced. Thanks again for the update and information. Sounds like you have been doing everythng right. I guess you have not been using any fuel injector cleaner, not that your injectors or valves were dirty. I wonder if your failed spark plug caused your problem.

The fact that your guy found the burnt valve is good, The fact that he hasn't seen it in Volvo's is even better. I really wouldn't worry about the guy hacking up your valve / head job. Just ask if they do head jobs often. I don't believe there is anything special about these cars as the job goes. Heck, guys on this site do it themselves with no real mechanic experience. Most will send the head off to a speciality shop to have the work done, likely the same place the stealer will use. Just ask the shop if they do heads and tell them that you would want all worn or damaged valves replaced. Usually exhaust valves burn, the car has 10 of them. Not sure if you need to have all 20 valves replaced. A good head shop will clean the head, inspect all the valves, replace all the worn & damaged ones and install new valve stem seals. Some people get new/rebuilt heads, that may be an exchange deal.

Letting the shop do it vs the Volvo dealer may be a cost difference of 50% to 75%. You can ask about a warranty to see if there is any difference there. Time and price would be my big concern. Also need to know why this all happened.

I have heard of these cars burning valves but not really often. I'm on these Volvo sites all the time and it's not uncommon to hear of people having more than 200,000 miles (320,000 km) with no valve issues. Way more common to hear about broken timing belts or a bad transmission.

My big deal is trying to figure out what caused the burnt valve. Sounds like you only had your hesitation issues for a few days. Not sure if you can burn a valve that fast? What brand spark plug was it? How old was the plug (miles/km)?

 

koch69:
Sounds like you have been doing a great job of maintaining this vehicle but at this mileage things are going to happen. If it were me, i would rebuild the head and the bottom end too (since you already mentioned it's using oil) considering the mileage.

But if you do this, and pay someone to do the labor, then you're going to spend more than the car is worth; especially since this is a '99 MY. This vintage is known for ETM and transmission failures (like rspi mentioned). So if you haven't already replaced/repaired those two items, then you're likely on borrowed time there too.

As far as replacing all the valves; i would ask the machine shop. Back when i wrenched professionally we would re-cut the valves (unless they were too heavily pitted) but not sure about modern valves; may not be surface-able.

BTW rspi; valves can burn up for any number of reasons; any data you may accumulate to support one theory or another (w/o strictly controlled test conditions) will be purely circumstantial.

 

GDog, yes, I do know that these valves can burn for several reasons but I'm trying to get a lead on it. Yes, I know one problem can be 180 different than the next but I'm really collecting as much data as I can at this point.

From what I have learned so far, lean fuel mix is a big cause for exhaust valves buring up and getting damage. Also valve stem leaks, carbon build up on valves, and the lack of exhaust back pressure.

Man, if it were possible to find some common cause on these cars it would be nice. I may be dreaming but please don't kick me for trying.

 

LOL.. not trying to kick anyone Man! Knock yourself out..

 

In changed the plugs with Volvo OEM plugs about 2000miles ago. I was surprised with the amount of deposits on the plugs. After the change the car ran very well. The Volvo tech is summing it up to age, mileage and possibly a bad plug that actually was broken in half. I don't think I am going to do the bottom end. gdog, your right the cost would be more than it's worth. The tranny is a 5 speed and so far no issues. The original owner abused this car and I'm afraid may have caused the oil burning issue. I had the dealer run a history and it looks like 3 oil changes in 30k miles. Plus the condition overall was not good. Bring a 5 speed Turbo, I think he just beat the crap out of it for 3 years on lease then turned it back in. I was always told by the Volvo service manager that these T5's were notorious for burning a bit of oil because of the high pressure turbo. He felt a liter over 5000kms was not bad, actually good. It took me a long time to get back to where it was suppose to be - wheel bearings, brakes, sensors, etc

What is your take on replacing the water, fuel and oil pumps since it will be apart? Timing belt, serpentine will get changed? Anything else that you think should be replaced? I appreciate your feedback.

 

That oil consumption is not bad. Sounds to me like that bad plug may have been the only cause of your problems. Did you car have a CEL?

Just a thought, if a manufacturer sells you a bad part, and it causes damage to your car, do they hold any liability? I guess it would be heck trying to prove the part was bad but give me a break, 2,000 KM's?

Do you remember dropping the plug when you installed it?

Other than my groans, I would do the t-belt, cam seals and water pump. Make sure they use OEM cam seals. Also do the PCV if it hasn't been replaced.

 

Thanks for the reply. A CEL did come on but long after the vibration on acceleration. The tech said the CEL was misfire in #2 cylinder. I never dropped the plug and I am always very careful when changing the plugs because of the aluminum head. I think I'm going to have to just get the head rebuilt and use OEM gaskets, water pump etc.
I'll keep you informed of what the outcome is. I found out because the car is over 10 yrs old that Volvo is giving a 15% reduction on labour and OEM parts. So I'm taking it back to them.
Thanks for your suggestions and ideas.

 

Sounds like a good plan. Let them know that their plug broke and likely caused your problem. Kind of a nudge to see what they have to say. I'm just wondering if a bad plug can burn a valve that fast or was it the straw that broke the camels back.

 

Aren't you stretching just a bit? More likely the opposite happened; a piece of the valve broke off and smacked the plug...

Get the head off and take some pics; might tell you something...

 

Heck, I don't know. All I know is that he said his car was missing, a day or so later he took it to the shop and they said it had a burnt valve and broken spark plug. Maybe you're right.

I'm trying to figure out how I can install cameras in all of my pistons, valve chambers, timing belt cover, etc. to watch and record every move the motor makes. The good thing about my code reader is that it will tell you what conditions were when a code is/was triggered.

 

Hey Koch,
I have to bring this back to life since I've run into the same problem, as my mechanic said. Engine showed a code for cylinder 2 misfire, tried a different plug, coil and checked in the injector so my mechanic is sure it's a valve. It's a nasty job from what he explains and I am wondering if you did yours and the details.

Hope to hear from you I have to make up my mind on the best approach for this situation.

Pej

 

It's not a nasty job, just a head job. I pulled the head off of our S70 a few months ago for a bad head gasket. Takes a while but you can do it if you have the tools and place.

I've been scratching my head over the past few years as to why so many of these cars burn valves and this is my opinion...
1. People use after market oil filters. OEM Volvo and Mann are the best to use. There are a couple of other acceptable ones, not many.
2. The after market filters cause the motors to start with less oil going into the head at start-up, starving the head for oil a little.
3. This slight starvation of oil at start-up causes the valve stem seals and lifters to wear faster than normal.
4. Once the valve stem seals wear, they start to leak on the valves and after a while it causes them to burn.

 

Would you happen to know what tools i would need for this job? pretty much every tool I would need?


I have done things like get an ABS module out of the car which is simple. But this job seems like it requires a lot of parts to come out.

Also, do you really think that filters would cause this issue? I always put synthetic oil and premium fuel in my car, my mechanic is stumped at why it would happen to me out of all the people. this really sucks.

 

Hey RSPI: I know you're interested in this topic of how/why valves get burnt because of your remarks above and also this thread.

And I agree with you that you should use good quality oil filters like Mann (think they are the OEM for volvo; yes?) but the main cause of burnt valves is excessive heat.

Upon googling the topic I found lots of BS theories out there but these two sites do the subject justice I believe:

Exhaust Valve Leakage - a photo essey

U.M.R. Engines


Hmm; you know my original reason for posting was to rebut your theory, but maybe you have something there...?

Accelerated valve guide wear can cause the valve to not seat properly; this will cause the valve to not be able to sink its heat to the valve seat and engine head causing the valve to run hot, and therefore...

Also leaking valve guides seals (often caused by worn valve guides) will allow excessive oil leakage down the valve stem and form carbon deposits on the inside of the poppet valve. These deposits are typically not uniformly distributed around the valve so they would cause a hot spot on one area of the valve, and again...

All that being said, you can have excessive heat in the combustion chamber for any number of reasons: detonation (bad knock sensors), lean condition (vac leaks or bad O2 sensors), carbon build up, etc. etc...

 

It was an expensive job. Replaced 2 valves on #2 cylinder, coil, serpentine belt, water pump gaskets etc. The Volvo tech also said that they have been seeing a number of Volvos with 250k+ km with burnt valves especially on the exhaust side. Now I have been using Mobil 1 10w30 synthetic oil, Man filters and usually Sunoco 94 octane fuel. The only thing that changed was that I had started to do a lot of short around town driving and only used Sunoco 94 3 out of 4 fills. The Volvo tech found that the valve that the piece came out of had a lot of carbon on the underside. He figured the gas was not an issue but the short driving did carbon up the engine. The tech stated that they had been seeing valve issues on 1998 -2000 s70. Possibly a run of defective valves. He also said, but a long shot, that the serpentine belt may have slipped. Stress on the engine and carbon seemed to be where he figured the real issue was.
It is an expensive job but worth it. I will be honest that for the first couple of thousand km after the repair , I was afraid to drive it, figuring that it was going to blow again. I does burn/leak a bit more oil now. Before the repair it was using 1 - 11/2 litres every 5000kms. It's just a bit more now but noticeable. I also notice that there is significant valve/tappit knock when you start the car after it has been sitting for a number of days. A bit unnerving when you hear the knock. As far as power, I notice now that it has a bit less torque than before.