98 v70 GLT rough idle when in gear

[rspi]

I've gone through this several times and done both head and engine swap. My prefer doing the head.

I see.more #2 burnt valves than all others combined.

[rspi]

Volvo S70 T5 Restoration, burnt valve, valve repl…:

[rspi]

The ABOUT comments of the videos have links to other related.videos.

Rebuilding a car motor cylinder head, part 1 of 3.:

[rspi]

I strongly suggest you check the.timing and compression yourself. Doesn't seem.like.there are any timing users to me. If so and.you really have low compression I would be.looking for.another.motor.

[draser]

Just thinking out loud here... what if you open the head up, remove old valves and find out the guides are worn out? Or the seats are worn and need recut, or are beyond repair? Or the head is cracked like this one guy had just posted about. Or one of the springs is broken or compressed. Hopefully mechanic included at least valve lapping and seal replacement in his quote.

[stephansvolvo]

Just thinking out loud here... what if you open the head up, remove old valves and find out the guides are worn out? Or the seats are worn and need recut, or are beyond repair? Or the head is cracked like this one guy had just posted about. Or one of the springs is broken or compressed. Hopefully mechanic included at least valve lapping and seal replacement in his quote.

I don't know. I guess it is a crap shoot for me. I wont know until I open it up. Luckily I can send all the parts back as long as they aarent installed.I am doing the work myslef and the machine shop will do the lapping for me.

[stephansvolvo]

Okay, here are the results of my compression testing tonight.
Dry:
1-115
2- 115
3- 115
4-0
5-115

Wet:
1-120
2-140
3-130
4-0
5-120
So what are your thoughts on these numbers? Am I looking at a new engine?

[erikv11]

So #4 is still zero, as you expected. But the others are too high and too uniform for there to be a bunch of bent valves, in my opinion. Was the timing actually off, if so how many teeth?

Did you do the test yourself? I'm wondering what you know about the accuracy of the gauge. If you think it is accurate, then the bottom is in bad shape, compression should be more like 150 - 180. Overall the numbers are pretty low for a turbo. But they are also pretty even so I am not convinced the engine is toast. Here are some comments on testing compression
- the engine should be warm (as in careful with those plugs, they might burn your fingers)
- pull the fuel pump fuse and let it run until it dies before you start the test
- you need to hold the throttle wide open while cranking
- crank it until the gauge stops going up, usually this is like 7 or 8 revolutions, not just 5 like you see in some how-tos

[stephansvolvo]

So #4 is still zero, as you expected. But the others are too high and too uniform for there to be a bunch of bent valves, in my opinion. Was the timing actually off, if so how many teeth?

Did you do the test yourself? I'm wondering what you know about the accuracy of the gauge. If you think it is accurate, then the bottom is in bad shape, compression should be more like 150 - 180. Overall the numbers are pretty low for a turbo. But they are also pretty even so I am not convinced the engine is toast. Here are some comments on testing compression
- the engine should be warm (as in careful with those plugs, they might burn your fingers)
- pull the fuel pump fuse and let it run until it dies before you start the test
- you need to hold the throttle wide open while cranking
- crank it until the gauge stops going up, usually this is like 7 or 8 revolutions, not just 5 like you see in some how-tos

I did do the the test myself. I let the car warm up not quite at the 3 position though.
The gage is brand new out of the box, doesn't mean it's accurate. I probably can hook it up to my compressor to check it for accuracy. I didn't check the timing. The mechanic said it looked like a couple of teeth. I will check this. Is there a best way to do this?

[erikv11]

That is plenty warm.

Gauge is probably fine but doesn't hurt to check. Cranked until the needle stops moving?

For checking the timing, look at the timing belt tutorials. Robert must have videos about it if you want to see it that way. Basically you want to raise the car on jackstands, remove the passenger wheel and put the crank on the mark, and then check the position of the cams. Are the cams on their marks, or off by a few teeth? Once the crank is on the mark it will be crystal clear where the timing is, by looking at the timing marks on the front cam gears and/or the slots on the back of the cams. Post up a pic if you are wondering about how to read the cams.