2004 s60 Won't start, low compression all 5 cylinders

[FREEBUSINESSES]

Wow, what a sad situation and even more sad final solution, change engines. Seeing that a few have had similar issues with low compression in all cylinders on these 2.5T engines, I have found myself with same brain wrecking issue.

I have done many head rebuilds, usually because of burnt valve or the typical timing belt jumping off from tensioners or water pump froze up which was my issue on my XC90 a couple years ago. Pump totally seized with no warning at all. And what was worse, it was only a year old with 15K on it. Lesson learned, do not buy cheap china crap from the well known autozone, advance like auto parts stores. Look at the labels, always buy the most expensive water pumps and tensioners is the lesson I learned.

Back to my latest dilemma. I picked up a clean 06 XC70 with same 2.5T where owner said it was running fine but blowing oil out exhaust front cam seal. He has a friend who replaced seal, but engine would not start afterwards. Friend gave up after no success, so engine was complete other than engine mount brackets, belt was on, but timing was off as I found, couple teeth estimate. They said they used cam lock, but engine would not start, so I rechecked and corrected timing, still no start. Keep in mind, I have done several head rebuilds with no issues.

So I did what most would do, check compression for fear of timing being out enough to bend valves. No compression on any cylinders, so my worse fear is they had timing so far out and trying to start over and over they bent all valves. Logical conclusion if not near impossible for all valves to be bent equally. Strange was my first thought as others here in this and other forums have debated over and over again with no solutions. I pulled head, and low and behold, there were nicks in piston tops thanks to the insane design of no tolerance engines. What ever happened to old school notched pistons? Think of the millions of dollars wasted for not notching pistons over the years on all these no tolerance motors. It would cost nothing for engineering to notch pistons which barely changes compression ratios, never mind this could easily be compensated with head modifications. This is called programmed failure by manufacturers to insure millions can be ripped off from owners with major repair costs at service departments. Just my little gripe on this design.

Sorry, I digress, slightly pissed off over this otherwise solid engine design. I have gone over 240K on a few with no issues with heads. Run premium fuels fools, don't be cheap, or do what I have done, put in octane booster and Lucas injector valve cleaner additives on regular once a month or every couple thousand miles. As well, use 100% synthetic oil and best oil filters. You should have no problem getting a couple to three hundred thousands miles on these engines.

Now onto the continuation of this mystery no one seems to have solved, short of an engine swap like with the excellent thread before this one on his dilemma dealing with so called expert mechanics which none seem to know half as much as they should, and why I do all my own work having been screwed many times by dealers and independents, disgusting how many inept mechanics there are out there, so BEWARE. Idiots, that is what I found dozens of times.

So when I pulled head, no valve damage that I could visually see. Nicks on pistons were obvious though. I did a valve leak test using acetone filling tops of valve combustion recesses in head, no leaks, now I was really confused. How could this be, zero compression yet no bent valves or head cracks. Sine I already purchased valves and seals, decided to replace them all and lap them in knowing this was a vehicle I wanted to keep for a while as it was clean and dealer serviced, not that this is good, but at least all oil changes were documented, not that this insures they were done, seen that scam more than a few times, no filter change, non synthetic oil used, etc. Another reason I do all my own services and repairs. So I put rebuilt head back on, set timing, double checked, and guess what, still no compression, as if I was surprised. LOL

So here we are with another forum dead end like many others, I read of similar problems, yet no solutions, sure wish people would post results instead of dead threads or worse, swap engines instead, not a good signal there is a solution, but every problem has a solution is my belief. Sorry for the rant, but I am very frustrated over this issue. I checked and double checked timing, did discover the VVT was not properly torqued, so maybe it slipped, so reset both VVT to cams and crank. Still zero compression in all 5 cylinders, what in the world is causing this impossible issue??? I did wet test as head was off for over a month, covered, cleaned piston tops, lubricated piston walls to keep from rusting as it was a very humid summer. What is confusing is seeing the same problem after head rebuild, no change, no start, no compression. Someone surely must have the answer out there. PPPPLLLLEEEEAAASSSSEEEE.
I have spare VVT.s, so will replace one at a time to see if the only thing I can't check is problem, no in and out play which can cause codes and leaks, so the mystery continues.

Thanks,

[FREEBUSINESSES]

Simply amazing so many people have had the same issue, yet none post what the solution was, other than one good thread where he gave up and swapped out engine. LOL How sad, all these years, all these same problems, all these forums, and no solutions.

[volvolugnut]

I will wade into this mess.
As you are aware, to have compression, you must have sealing rings, head gasket and valves. Any of these can be leaky and you will have low compression instead of no compression. You are also likely to have varied low compression on the cylinders.
To get compression reading you must have one more thing - valves closed on the compression stroke. This seems to me to be the missing thing. I Know you said you triple checked the timing, but something has gone wrong.
You are likely also aware the timing mark on the crank is not on top dead center, but some other position. This can be confusing to someone used to other engines.
Go back to basics. Determine when the piston is up by removing as spark plug and poking a stick in the hole. Then visually determine the valve position perhaps through the oil fill hole?
When shady mechanics do work, mistakes can be made and marks changed. Something has gone strange here. Do you have a timing belt with the alignment marks on the back side? Do they position correctly? Are tensioners in the proper location? Belt routing correct?
volvolugnut

[firstv70volvo]

Simply amazing so many people have had the same issue, yet none post what the solution was, other than one good thread where he gave up and swapped out engine. LOL How sad, all these years, all these same problems, all these forums, and no solutions.

Have you carefully checked the crankshaft timing belt pulley inside splines? They can become stripped out and allow the pulley to rotate some on the crank. Timing marks on pulley may look correct but the crank it not in the correct position if the pulley has rotated some. The splines can look okay just viewing them while the pulley is on the crank but look at the photos and you'll see the splines are stripped internally back from the end of the timing belt pulley. You have to pull it off to get a good at the condition of the splines. A crank locking tool may help confirm this type of problem although I've never used one.

[jonesg]

Simply amazing so many people have had the same issue, yet none post what the solution was, other than one good thread where he gave up and swapped out engine. LOL How sad, all these years, all these same problems, all these forums, and no solutions.

I had the problem but didn't run the engine, it was out of phase during a belt and cam seal job.

more recently the crank pulley retaining nut vanished and allowed the pulley to wobble freely on the crankshaft.
new pulley and nut fixed that near disaster.

I would say yours is completely out of phase and agree you ought to check the crank pulley.
Remove pulley and inspect crankshaft splines. I always seem to have to dig deeper to reach the sunlight.

[SuperHerman]

I know I am late to the dance, but I had a similar experience with an S80 2.9 na.

After replacing the head gasket and one piston ring set I got it up and running without any issues.

I gave the car to my sister and months later she had similar problems to yours. A new used engine was installed and still problems. Finally it was determined that the second cat was clogged and the back pressure was the cause of all the funky make no sense lack of compression readings. Mechanic decided to verify his theory by welding in a straight pipe for the second cat and the issue was solved.

So, if you have problems in the future check the exhaust pressure. Theory forwarded was all the miles on the failing head gasket destroyed the cat.

[abscate]

If you had compression pre valve job, then you hit the valves sometime during refit, and need to re do that job.

Tough love , but if timing lines up now, and compression is zero across all five, it’s valves

Not even a block crack would kill all five.

Are you confident in your instrument? Have you measured a well running vehicle with it?

[FREEBUSINESSES]

Thanks, yes, I am certain there is no valve damage because when I obtained vehicle, I did compression test since whoever worked on replacing exhaust cam seal screwed up timing. So there was no compression when I got vehicle, and when I pulled head thinking valves were all wiped out, none were??? I did leak down test on head and valves with acetone, no leak down, so I replaced and lapped in new valves since I had already purchased them ahead of tear down. Put in new valve seals, cleaned up head, put head back on, timed it properly, no issue with valves hitting pistons, no restriction on manual turning crank. By the way, there were piston valve nicks when I took it apart, and previous owner said he heard valve hits when it would not start, so yes, timing was out of whack, but not now, and still no compression, no change??? It defies logic why all cylinders would be about zero compression. Since I do not know history of previous work on vehicle, I am at a loss. I have seen many bent valve motors, and in every case, not every valve was bent enough to have zero compression on every cylinder, maybe two or three, but not all. Where cams stops is where it stops, not possible for all valves to be damaged in any one spot, right???

Sounds weak, so even without compression gage you can tell there is no compression. Checked anyhow to see what readings were, and one and five had 15lbs, others zero??? I tried the oil in cylinders and let it stand for several days thinking the issue might have been what a few others had mentioned about fuel washing down cylinders of oil. I disconnected injectors to avoid this issue, so no change. I checked near top dead center of piston one, so timing is right on. The one question I have is this, I have seen all the forums, and the cams ID is throwing me off on end of cams. Some pictures are reversed as to the ID being on intake cam being on bottom and exhaust cam ID print on top. Not knowing if these pictures were in time properly or not, it was confusing and I don't know which is correct. Cam lock seemed to align cams without issue, although there was a chip on end of cam from previous hack who worked on replacing exhaust valve seal and not putting VVT on time properly. Does anyone remember which cams have which ID numbers up or down when setting timing??? Could cams be out 180 degrees??? I put cams back the way they came out as I took pictures.

Thanks.

[FREEBUSINESSES]

Any pictures of crank pulley when set to proper timing mark, this would show relationship of the four bolts in relation to crank pulley rather than pulling of crank pulley. Eyeballed it, looks fine outside, but looking at that crank pulley in picture, amazing, would not believe it if I didn't see it, but that happened due to missing bolt as it sounds like what happened.

[abscate]

The notch on the crank pulley goes on the nub on the block. Very simple.

The cam lock tool ensures the cams are in the correct phase. Given you starting with an engine that has been messed with , you need to start at the basic cam alignment with the cam tool