Cyl head valve issue

03 vue 3.0 motor. Dohc. 4 cams. Just got it. Owner did recent timing belt and seemed ok until it wasn’t. Would not crank. I pulled timing cover. Belt is fine. Timing marks are right on. Crank will only rotate 30deg? Took off valve covers. U lock both intake/exhaust sprockets with tool. Than install belt. I took off belt and basically 1 sprocket sprung about 30 deg but the other 3 stayed in place. Since each cyl has valves in different state of open/close. Crank will now rotate 360 deg. I Looked at lifter buckets. All seem same height. I applied pressure to all and they feel same stiffness. What’s next?

So the engine ran fine for a while, then suddenly crankshaft wouldn’t turn?

I think so. i got it for scrap value. $300. Seller was real talkative about fixing this and that but I never really did get a timeline. He said it ran poorly to start. He blamed that mostly on shot exhaust/cats. He spent 800 on new exhaust. I am not sure when he did timing belt. He wanted to put in used motor per his mechanics advice but would have been way over its value. He didn’t want someone to part it out and was pleased to hear I might try and fix it. He even wants me to contact him after I fix it.

This is an Opel motor and when my Granddaughter had one she could not get a mechanic to work on getting hers running, She lived 60 miles from me so I talked to my mechanic, he said “Don’t bring it to me, the repairs get so expensive so fast the I have had two people abandon the cars at my shop rather than pay the bill.”

She found an old German mechanic who took it on as a personal challenge to get it running and I believe that when she got it back, there was nothing inside her 4 catalytic converters which would have cost $1000 each.

It sounds like one sprocket jumped time and you probably have valve and/or piston damage. At this point you should be glad you only paid $300.

this is our 3rd 3.0 vue. Kid got one 5 yrs ago. Zero issues. I did timing belt when we got it. I picked up 2nd 2 months ago for some reason. Runs fine. I got 3rd since it had new exhaust. And tires. The timing belt was timed correctly. Was it replaced for a reason? Motor is 1/2 stripped down now. the exhaust cam is over the head bolts so the cam has to come out first. i think the tear down process is a little more complicated than i first thought

Yes when you got it. But something is obviously wrong…it’ll be interesting to see what you find.

plenum is off so I can see intake valves easy enough. i rotated all 4 cams and they all turn with the same effort. each cyl feels the same. 1 or 2 do not feel any harder to turn. i was thinking of pouring in some gas into intake port and see how quick it runs down into cylinder. heard that is an old mechanic trick to see if valves need grinding or lapping

Talked to seller. He did timing belt as maintenance. Not to fix broken belt. Drove vue for 1 month till it stalled. Would crank but not fire. I approached it as timing belt issue till I pulled timing cover and see all 4 cams are right. But, I cannot see crank timing mark? Hmm, did belt slip on crank?

Of course they all feel fine now, you have the belt off. The one that sprang 30 degrees was obviously out of sync with the other 3 and the crankshaft and that is the one that was holding a valve open far enough to stop rotation as long as the belt was holding everything together.

cam kit includes cam sprocket locks since valve springs will push/rotate at least 1 cam if you remove belt. if all 4 cams stayed put than you wouldn’t need cam locks.

I stand corrected:)

Just curious, did you try to measure the compression? I mean before you started to take the engine apart?

I think what you got there is a interesting $300 adventure. And it’s hard to find a good adventure for that price any more. Good for you for figuring out what’s wrong and fixing it.

I assumed timing was off so I did not want to crank motor. Checking compression would require more cranking. I removed timing cover first. All cams are lined up? Rotated motor with ratchet. Only got About 30 degrees till it stopped. Ur point about new belt after old one broke sounded good till seller said that did not occur.

Put the timing belt back on with all timing marks correct and see if the crankshft will manually turn.

crank pulley is bolted to crank flange with 8 bolts. Or is it 6? No timing Mark on pulley. It’s on small flange. It’s hard to eyeball tdc unless u have proper tool that bolts to crank flange. I will figure something out. Pic shows tool on crank. And alignment device for cams. Pretty slick tool kit. I rented 1 before. They have cheapo plastic kits for $70 or so online.

motor cranks easy with no spark plugs. Cranks almost same with plugs. I checked compression. Not good. Like zero.

Is this with the timing belt re-installed with all timing marks correct?

Try a wet compression test, going through similar with daughters Saturn hoping crank sensor.

Yes timing belt is on and all marks are correct. I initially cranked motor with no plugs and with no compression it had real smooth cranking. Ok, install plugs and it almost sounded the same. I had helper crank motor so I could watch sprockets turn. timing cover is off. I had gas in intake ports a few days ago to check for valve sealing. So maybe the gas washed down the rings? I added 2-3 oz oil per plug hole and cranked with plugs out. No difference in compression reading

Well . . . what WERE the compression readings? :thinking: