Great method, what also works for me is a small mini lathe (or a regular one) and a dial gauge. You really can't tell by looking at it, the spinning shows alot.
Good, glad someone with experience checking valves this way agrees with my method! Using the dial gauge is a great idea. I’ll do that next time. Thanks for the comment!
Easiest way to check for bent or leaking valves is spray some carb cleaner in the ports while assembled. If it leaks out then it’s a bent valve or burned seats. Method two if the heads are apart is put the valve in the guide and open/close the valves firmly contacting the valve seat a few times and listen. A bent valve makes a very distinct sound when it contacts the seat vs a good valve.
Hello. Yeah, those methods would totally work and are I’m sure more reliable. The drill press method was just a haphazard idea I thought might be useful as far as a quick and dirty way to test. Thanks for the suggestions!
@@FastFixUA-cam what your doing is just fine, it’s a good idea using the drill press. Whenever we would get heads into the shop the method I described were used as a quick check on the condition on the valves and seats. If the valve guides are severely worn the valve face can develop a weird pattern that makes it look like the valve is bent but is easily fixed when refacing the valve in a valve grinder. If you listen when opening/closing the valve “bounce the valve off the seat” the sound of a bent valve is unmistakable. Saw so much carnage on cylinder heads with bent up ruined valves it’s amazing the pistons didn’t get destroyed sometimes.
@@South_0f_Heaven_ wow, I believe it. I don’t have much experience in the machine shop world or engine building for that matter. I’ve done my share of garage motors, but nothing too fancy. I can imagine the carnage is both interesting and dumbfounding. As in “how the hell did this happen?” Thanks for the nice comments. It’s greatly appreciated.
@@FastFixUA-cam lol yeah I’ve been on both sides of it. Put a lot of questionable things back together before many times. Never had a head checked for cracks, leaky valves, warpage just do a visual clean it up and put it back together hope it runs lol. Then I got to see it from a machine shops perspective and it opened my eyes to the litany of problems that can happen. Just trying to pass a little knowledge down to everyone, lot of times machine shops are daunting to guys that work at home and it’s hard to find a good shop that’s not overpriced, does work in a timely manner and doesn’t have a general bad attitude towards its customers. Always heard horror stories about people dropping engines and heads off only to have them sit in limbo until the shop feels like working on them. Nobody wants to wait 3-6 months to have a block bored/honed or to be fully rebuilt either. Far as cylinder heads go it doesn’t cost much to have a shop check the overall condition of the heads and it’s money well spent to be honest. Best way to look at it is if you put it back together and it’s no good your out money for the gaskets and your time, having a shop check them out gives you peace of mind and costs less then having to buy gaskets again and the time involved.
I’m no head valve expert, but in my opinion, yes. On the one hand, if you have a good valve to valve seat seal even with a slightly bend valve your engine should perform properly. However, a slightly bent valve would be under more pressure from the valve spring and could crack or break causing catastrophic failure. I’d like to have a professional give opinions on this, but I think my intuition is reasonable. That said, valves for these heads are $16 each and I’m not going to spend that kind of money on these heads. So, we’ll see. I’ll probably reuse them and keep my fingers crossed.
Hi thanks for the video great idea. I’m in a similar situation rebuilding a Porsche engine and had difficulty removing some of the valves. Did you have to get the valve guides replaced too? Thanks
Hello. The valves didn’t come out as easy as they should on this motor either. Honestly, the valve guides should’ve been replaced, but I went cheap and rationalized using them as-is because these heads will be replaced with aluminum heads in the not so distant future. Good luck on the Porsche engine. Sounds like a fun job 👍
This is pretty cool I’m gonna try it, I have one cylinder with no compression after a snapped belt. They look ok on first glance but I think they’ve gotta be bent.
@@FastFixUA-cam how bent do you think they’d need to be to cause zero compression? I removed the valves from that cylinder and spun them in the drill press and I’ve gotta say they really don’t look bent at all. No worse than the small wobble you have in the video so I’m kinda confused lol..
@@bendude6748 hey man. Can you explain a little more in regard to having zero compression? You’d need significant valve, head, or block damage to cause a zero compression situation. Usually a bent valve will cause a low compression reading then eventually a zero reading as the pressure leaks out as you stop the compression test. A slight wobble in the valve shouldn’t cause a zero reading.
@@FastFixUA-cam so basically when the timing belt snapped it broke two rocker arms which is common on these engines it’s a 2.0 CDTI Diesel Vauxhall engine. Anyway I timed it back up with a new belt, car really struggled to start so I compression tested cylinder 1-3 were all good with 200psi, on to cylinder 4 and the compression tester just jumped up slightly and immediately back down to 0. I assumed badly bent valves and pulled the head off but they look like they’ve not been touched or if they have they’ve not had a big impact. Can’t see any damage to the bottom end but wish I had done a leak down test before ripping it apart.
@@bendude6748 gotcha. Yes, a leak down test would be the thing to do, but obviously that can’t happen now. But, you sorta know what the test would reveal: That you have a leak somewhere. Question is, where? I assume cylinder 4 was the cylinder with the broken rocker arms? I’d focus on that aspect of the issue. Such as (and I’m not trying to offend you) did you install the new rockers arms correctly? Ie: setting lash and preload within specs at TDC. Not sure how your rockers are mounted, but I’m picturing a shaft mount system on your diesel. If so, make sure the shaft didn’t take damage and bend. If your visual inspection of the head, head gasket, piston, and block don’t raise any concerns, the problem has to be with the valves or rocker arms. After all, the rocker arms are the parts that literally broke. I’d at minimum replace the valves regardless. If they bumped the piston, their integrity is compromised and could cause problems in the future and lessen the performance of your motor. I’d check the valve guides too. Could be a contributing factor. Sorry if this wasn’t much help. Let me know how things go.
My honda odyssey broke a timing belt and its an interference engine. I will put a new belt on and run a compression test and just replace all valves in affected cylinders. Frigging expensive to replace all of them as planned since mine is i-vtec with vcm☹️☹️ if i replace belt and it runs good i will GO PLAY LOTTO😂
You are a creative guy! I learned from you. I like the board and how to separate the and organize the value. Well done. Thank you for sharing.
You are welcome! I appreciate the awesome comment 👍
Great method, what also works for me is a small mini lathe (or a regular one) and a dial gauge. You really can't tell by looking at it, the spinning shows alot.
Good, glad someone with experience checking valves this way agrees with my method! Using the dial gauge is a great idea. I’ll do that next time. Thanks for the comment!
Funny I thought of that last week putting the valves out and it seems it works! Definetely will try that to.
Great minds! 🧠
Thanks for this method!! I was wondering why my valve wouldn't fit correctly. Valve didn't look bent but was..
You bet! Yes, sometimes very hard to tell. 👍
Easiest way to check for bent or leaking valves is spray some carb cleaner in the ports while assembled. If it leaks out then it’s a bent valve or burned seats.
Method two if the heads are apart is put the valve in the guide and open/close the valves firmly contacting the valve seat a few times and listen. A bent valve makes a very distinct sound when it contacts the seat vs a good valve.
Hello. Yeah, those methods would totally work and are I’m sure more reliable. The drill press method was just a haphazard idea I thought might be useful as far as a quick and dirty way to test. Thanks for the suggestions!
@@FastFixUA-cam what your doing is just fine, it’s a good idea using the drill press.
Whenever we would get heads into the shop the method I described were used as a quick check on the condition on the valves and seats.
If the valve guides are severely worn the valve face can develop a weird pattern that makes it look like the valve is bent but is easily fixed when refacing the valve in a valve grinder.
If you listen when opening/closing the valve “bounce the valve off the seat” the sound of a bent valve is unmistakable.
Saw so much carnage on cylinder heads with bent up ruined valves it’s amazing the pistons didn’t get destroyed sometimes.
@@South_0f_Heaven_ wow, I believe it. I don’t have much experience in the machine shop world or engine building for that matter. I’ve done my share of garage motors, but nothing too fancy. I can imagine the carnage is both interesting and dumbfounding. As in “how the hell did this happen?” Thanks for the nice comments. It’s greatly appreciated.
@@FastFixUA-cam lol yeah I’ve been on both sides of it. Put a lot of questionable things back together before many times. Never had a head checked for cracks, leaky valves, warpage just do a visual clean it up and put it back together hope it runs lol.
Then I got to see it from a machine shops perspective and it opened my eyes to the litany of problems that can happen.
Just trying to pass a little knowledge down to everyone, lot of times machine shops are daunting to guys that work at home and it’s hard to find a good shop that’s not overpriced, does work in a timely manner and doesn’t have a general bad attitude towards its customers.
Always heard horror stories about people dropping engines and heads off only to have them sit in limbo until the shop feels like working on them. Nobody wants to wait 3-6 months to have a block bored/honed or to be fully rebuilt either.
Far as cylinder heads go it doesn’t cost much to have a shop check the overall condition of the heads and it’s money well spent to be honest. Best way to look at it is if you put it back together and it’s no good your out money for the gaskets and your time, having a shop check them out gives you peace of mind and costs less then having to buy gaskets again and the time involved.
Thanks. So if it’s slightly bent it’s no good hih
I’m no head valve expert, but in my opinion, yes. On the one hand, if you have a good valve to valve seat seal even with a slightly bend valve your engine should perform properly. However, a slightly bent valve would be under more pressure from the valve spring and could crack or break causing catastrophic failure. I’d like to have a professional give opinions on this, but I think my intuition is reasonable. That said, valves for these heads are $16 each and I’m not going to spend that kind of money on these heads. So, we’ll see. I’ll probably reuse them and keep my fingers crossed.
Hi thanks for the video great idea. I’m in a similar situation rebuilding a Porsche engine and had difficulty removing some of the valves. Did you have to get the valve guides replaced too? Thanks
Hello. The valves didn’t come out as easy as they should on this motor either. Honestly, the valve guides should’ve been replaced, but I went cheap and rationalized using them as-is because these heads will be replaced with aluminum heads in the not so distant future. Good luck on the Porsche engine. Sounds like a fun job 👍
@@FastFixUA-cam thanks 🙏🏼
This is pretty cool I’m gonna try it, I have one cylinder with no compression after a snapped belt. They look ok on first glance but I think they’ve gotta be bent.
Yes, I’d say so for sure. Not many other reasons why you’d have no compression other than a bent valve.
@@FastFixUA-cam how bent do you think they’d need to be to cause zero compression? I removed the valves from that cylinder and spun them in the drill press and I’ve gotta say they really don’t look bent at all. No worse than the small wobble you have in the video so I’m kinda confused lol..
@@bendude6748 hey man. Can you explain a little more in regard to having zero compression? You’d need significant valve, head, or block damage to cause a zero compression situation. Usually a bent valve will cause a low compression reading then eventually a zero reading as the pressure leaks out as you stop the compression test. A slight wobble in the valve shouldn’t cause a zero reading.
@@FastFixUA-cam so basically when the timing belt snapped it broke two rocker arms which is common on these engines it’s a 2.0 CDTI Diesel Vauxhall engine. Anyway I timed it back up with a new belt, car really struggled to start so I compression tested cylinder 1-3 were all good with 200psi, on to cylinder 4 and the compression tester just jumped up slightly and immediately back down to 0. I assumed badly bent valves and pulled the head off but they look like they’ve not been touched or if they have they’ve not had a big impact. Can’t see any damage to the bottom end but wish I had done a leak down test before ripping it apart.
@@bendude6748 gotcha. Yes, a leak down test would be the thing to do, but obviously that can’t happen now. But, you sorta know what the test would reveal: That you have a leak somewhere. Question is, where? I assume cylinder 4 was the cylinder with the broken rocker arms? I’d focus on that aspect of the issue. Such as (and I’m not trying to offend you) did you install the new rockers arms correctly? Ie: setting lash and preload within specs at TDC. Not sure how your rockers are mounted, but I’m picturing a shaft mount system on your diesel. If so, make sure the shaft didn’t take damage and bend. If your visual inspection of the head, head gasket, piston, and block don’t raise any concerns, the problem has to be with the valves or rocker arms. After all, the rocker arms are the parts that literally broke. I’d at minimum replace the valves regardless. If they bumped the piston, their integrity is compromised and could cause problems in the future and lessen the performance of your motor. I’d check the valve guides too. Could be a contributing factor.
Sorry if this wasn’t much help. Let me know how things go.
Awesome idea.
Thanks!
Your drill and chuck matter of fact the whole drill was wobling which made the valves looked wobbly. Lol the valves were probably fine
Promise you they were not. But I take your point.
very good video!
My honda odyssey broke a timing belt and its an interference engine. I will put a new belt on and run a compression test and just replace all valves in affected cylinders. Frigging expensive to replace all of them as planned since mine is i-vtec with vcm☹️☹️ if i replace belt and it runs good i will GO PLAY LOTTO😂
Oh boy….a broken timing belt or chain is usually catastrophic with interference engines. Best of luck!
Less talking helps
So you’re into a little less talk and a lot more action?