2.5t timing belt broken need help with leakdown test

68lemans462 · Post by **68lemans462** » 16 Apr 2019, 17:35

Today while driving at about 10mph I heard a noise. I parked and noticed antifreeze dripping from the cam cover. I picked up my wife, restarted car, car ran ok. Car then died another block down the street and upon quick inspection I determined the belt broke. I'm guessing a potential water pump failure which took the belt with it. The pump belt and tensioner were replaced 50k miles ago.

I'd like to do a leakdown test to see if valves are damaged. How can I properly align the cams so all valves will be closed when testing a particular cylinder? Any tricks to this?

Post by **RickHaleParker** » 16 Apr 2019, 18:22

68lemans462 wrote: ↑16 Apr 2019, 17:35 How can I properly align the cams so all valves will be closed when testing a particular cylinder? Any tricks to this?

Take the Cam Cover off. That will close all 20 valves. Unless there is damage.

tardcart · Post by **tardcart** » 16 Apr 2019, 18:50

Thats a big job just for a leak down test. though you may be doing it anyway if most likely valves are bent. There is nothing wrong with a compression test for this diagnosis. The problem will be highly noticeable like 0 to 50 psi if you have had contact. Tell us the pump name for hall of shame.

tardcart · Post by **tardcart** » 16 Apr 2019, 19:07

should add; compression test after retiming. that means a new pump and belt, which is still less work than R&R cam cover.

68lemans462 · Post by **68lemans462** » 16 Apr 2019, 19:30

In terms of retiming.... I can turn the crank by hand and have turned it several times and left it in different positions. In each crank position I have tried to turn the cams and they only turn a little bit about the same amount each. Shouldn't the cams turn? I would expect the cams to turn more or less based on the position of the crank/pistons ... What am I missing?

68lemans462 · Post by **68lemans462** » 16 Apr 2019, 19:34

Also is this thing guaranteed to have bent valves or are there some who get "lucky"? ... The belt let go at idle sitting at a stop light.

Post by **RickHaleParker** » 16 Apr 2019, 19:40

68lemans462 wrote: ↑16 Apr 2019, 19:30 What am I missing?

It is a interference engine. You are not turning the crank and both cams in synchronization and the valves are interfering with the pistons
.
Take the cam cover off, closes all 20 valves and eliminates the interference so you do the leakdown and compression test.

68lemans462 · Post by **68lemans462** » 16 Apr 2019, 19:56

OK makes sense. Thanks much for your suggestions and sorry for my rookie questions I LOVE THIS SITE! .... Can someone please post a link to the cam cover removal procedure? I seem to remember a couple specialty tools and specific method needed?

I'm unsure what to do with this car! I like the car and it runs great (or did) but it isn't worth anything! It has 140k on the odo and runs great doesn't use any oil. Tyranny is solid and I've done front end work, etc and kept it nice. Planned to drive it to the grave with several hundred on the odo. I figure I habe nothing to lose in tearing it down and diagnosing but unsure how interested I am in fixing it and in pretty sure it will be too spendy given the vehicle value to have someone else do it. I'm a competent and experienced mechanic but I've never had the head off a Volvo engine... How scared should I be? How much is head work? I'm guessing most have a valve job done while the head is out for good measure?

tardcart · Post by **tardcart** » 16 Apr 2019, 20:08

you can never get lucky if the belt broke, not just skipped three teeth. Even at idle. skip all the testing and just make a decision on if you want to do the job of removing the head and replacing at least 8 valves. you would have to do it as not worth paying for it along with risk they'll do it wrong. You can do it wrong too, but thats a learning experience instead of a rip off.

68lemans462 · Post by **68lemans462** » 16 Apr 2019, 20:15

tardcart wrote: ↑16 Apr 2019, 20:08 you can never get lucky if the belt broke, not just skipped three teeth. Even at idle. skip all the testing and just make a decision on if you want to do the job of removing the head and replacing at least 8 valves. you would have to do it as not worth paying for it along with risk they'll do it wrong. You can do it wrong too, but thats a learning experience instead of a rip off.

OK fair enough, I know all about paying for an "education" ... What is a ballpark parts cost to diy the job including head work assuming it needs 8 valves as you say.

I plan to at least yank the cam cover and do a leakdown and comp test.. Proof is in the puddn' and unfortunately so may be reality!