ZERO compression on all 5 cylinders

vcolper · Post by **vcolper** » 22 Jan 2016, 20:54

I'd like an expert diagnosis before tearing apart the engine.
Going back from the start:
I purchased the car as is.... not running.
According to PO car was running fine, and on the way home it stalled. Engine stopped. Would not start.
Now by "not starting" I dont know if the PO meant it was turning over or if it was cranking but not starting.
When I got the car the battery was dead.
Battery was replaced and I tried to start it, but it would just turn over like an engine with no compression.
I found the Alternator serpentine belt was missing. (Quick fix I thought!)
I installed one. Engine would crank, but not start.
Then:
I checked the timing belt to see if it broke or for signs of slipping or broken teeth. All there, belt is good. Belt is not new, But its all there, intact.
I checked the timing. Cyl @1 at TDC, both camshaft marks aligned and crankshaft also at its mark. Timing is correct.
I checked for compression on all c 5 cylinders. All read 0 psi. Tested the compression tester on another engine. Compression tester is good.

Now, I'm no master mechanic, but I pretty much can figure engines out (I think).
I find it hard to believe that all cylinder would have "0" compression due to bad rings or bent valves.
It's like if the valves aren't opening and closing at all. Could it have to do with the VVT? I know nothing on how that works. (I plan on reading something on the topic).

Any suggestions? before I tear it apart.
Thanks

Post by **jimmy57** » 22 Jan 2016, 21:10

The cam and crank marks should not be aligned if #1 is at TDC. This engine, like so many these days, times at a point safe for for automated assembly with no pistons at TDC where valve contact could occur.
If it is really at verified TDC then there is a problem. The crank is splined with one master spline with the crank gear fitting using the master spline. It is hard for it to be in the wrong spot but not impossible. Did it look like it had been wrenched on recently? Anything look odd?

vcolper · Post by **vcolper** » 22 Jan 2016, 22:02

Thanks Jimmy. Ill look in more detail at the crank, but no recent "wrenching" apparent.

JudgeRat · Post by **JudgeRat** » 22 Jan 2016, 23:47

This sounds suspiciously similar to the experiences I've had recently:

https://www.matthewsvolvosite.com/forums ... =9&t=69529

If the VVT is out of whack, that definitely would blow your compression tests and make starting difficult or impossible depending on how badly it is out.

Post by **precopster** » 23 Jan 2016, 14:03

Jimmy is very literal in his interpretation of timing marks because other Volvo whiteblocks use the same timing marks yet piston #1 is nowhere near TDC.

On a 4 banger not certain where TDC is in relation to timing marks so tread carefully and find the marks on crank then compare with cams. It could be in this case that a new belt/tensioner was fitted in a last ditch attempt to repair. The missing serpentine is certainly evidence of that. No compression means bent valves.

Post by **alschnertz** » 23 Jan 2016, 14:31

5-cyl? Must be after 2005-1/2.

I'd suspect a timing issue too. I think the VVT has to be "pre-loaded" when aligning the timing marks on later engines.
The 1.9L 4-cyl engines did not need to have the VVT pre-loaded.

vcolper · Post by **vcolper** » 08 Feb 2016, 21:03

OK Im back after a long break from the V50. I disassembled and found the timming belt was "shredding" and the debris got wrapped around the crankshaft sprocket causing the belt to slip. I also found the belt tensioner not very tight.

Quite a mess
From the top of the camshafts the belt looked fine.
Anyhow all 20 valves have impacted the pistons and most valves are bent. Fortunately the pistons were only scarred.

Now I am trying to identify the part numbers for the intake and exhaust valves. It's a 2005 Volvo V50 T5. It has the 5 cylinder TURBO engine.
Cars VIN :YV1MW682952043668
Any suggestions on where to get them.....inexpensively. Ive seen prices from $7.00 up to $85 per valve.

Post by **precopster** » 12 Feb 2016, 06:13

Try a machining shop where they have access to cheap quality valves. My local machinist is providing intake valves for $15 each and because he uses them in his rebuilds he stands by them.

FREEBUSINESSES · Post by **FREEBUSINESSES** » 27 Sep 2020, 09:39

So why after all these years and so many having zero compression in all 5 cylinders even when valves are all good, or changed and lapped in, still zero compression, and timing is triple checked, so why does this mystery have no solutions.