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Thinking out loud here…what if I got some mild cold rolled steel and made me a “cap” for #2’s intake port? Use some rubber gasket material to insure a leak free seal? I don’t believe I have a clamp that would fit over the head but I could drill a couple holes in my plate and use the intake manifold bolt holes to tighten it down. It would quantify to me if the valves are leaking, or it is indeed the bottom end.
That would work. You could also use RTV to seal it.
 

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Discussion Starter · #102 · (Edited)
Alright, so I had a bit of time to make me a plate. I used a rubber toilet flange to seal it. This was only on the intake side, too. The leakdown improved to 20% (was 30%). Is that significant enough to say the bottom end is OK? I can’t quantify how well the seal was (or wasn’t) on my block off plate. The rest of the cyls are 10%, so #2 is still low compared to the rest. I guess I need to make one for the exhaust side tomorrow and see how that goes.

Light Motor vehicle Gauge Clock Automotive design
 

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Alright, so I had a bit of time to make me a plate. I used a rubber toilet flange to seal it. This was only on the intake side, too. The leakdown improved to 20% (was 30%). Is that significant enough to say the bottom end is OK? I can’t quantify how well the seal was (or wasn’t) on my block off plate. The rest of the cyls are 10%, so #2 is still low compared to the rest. I guess I need to make one for the exhaust side tomorrow and see how that goes.

View attachment 141639
Most parts stores sell gasket material in several different materials. Might work a bit better for you.
 

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Discussion Starter · #104 ·
Most parts stores sell gasket material in several different materials. Might work a bit better for you.
I can do that, but do you think it’s worth it? Or should I pull the damn head for the 10th MF’in time and lap the valves myself? I know, no one can say 100% it’s the head without being here in person but what say the group? I value everyone’s opinion.
 

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I can do that, but do you think it’s worth it? Or should I pull the damn head for the 10th MF’in time and lap the valves myself? I know, no one can say 100% it’s the head without being here in person but what say the group? I value everyone’s opinion.
the gasket material was a recommendation instead of toilet flange seal. I think you try blocking off the exhaust side and seeing if it gets any better. It's virtually free minus time and will let you know what your working with. I've been there just getting frustrated but it'll be ok just try and figure out what's wrong and where youre standing.
 

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Discussion Starter · #106 ·
It's virtually free minus time and will let you know what your working with. I've been there just getting frustrated but it'll be ok just try and figure out what's wrong and where youre standing
I’ll try and make a cap for the exhaust side port tomorrow, and see how that goes. I may pick some gasket material up too - May have to wait til the freakin weekend.

Hell yes brother I am frustrated beyond belief. Appreciate the kind words. Glad I got my 08 Solara to daily in the meantime. This hog ain’t exactly kind at the gas pump. If I ever get it back on the road it’ll be a different car. Twin disc clutch and I’ve really cleaned up the engine harness.
 

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I’d say, cap the exhaust side just to be sure and go from there. There may be something wrong with the head. I can’t believe that two machine shops could mess up one cylinder twice. There must be something going on with the valves or the seats.
 

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Discussion Starter · #108 ·
cap the exhaust side just to be sure
I will. I tried tonight, but didn’t have a piece of plate big enough to cover the exhaust. I tried just sandwiching a smaller piece of plate under the turbo manifold. I couldn’t get it bolted down evenly so it leaked. A lot. The way I had it, it was concentrating and blowing the air straight up. So I’m pretty sure it’s something with the valves/seats, like you said @ill_mannered. When I pressurize cyl #2, if I don’t have it at TDC or BDC perfect, it’ll spin the crank around and you can’t hold the ratchet on the crank bolt. It’ll jerk your arm pretty good. I just don’t think it’s the bottom end. I know, I’m wishing for it to not be and biased looking for any thing to rule out before I go that route.
 

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I just don’t think it’s the bottom end.
I really don't think so, either. But your big loss in compression on #2, followed by two valvejobs by different shops - both resulting in leakage on #2 is bewildering.

I've touched base with several fellow engine-guys about your issue and we're all in agreement:

1. The sequence of events and circumstances don't add up.
2. It'll probably run just fine, now - but
3: A fresh quality valvejob should not leak....at all.

One thing you might try if you haven't already: using a rubber mallet, or a hammer and (suitable material non-marring) punch - give the valves a rap to unseat them a bit and give them a chance to "slam" shut again - then re-test. This might allow the valves to find a happier seating spot and provide better test results.
 

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Discussion Starter · #110 ·
followed by two valvejobs by different shops - both resulting in leakage on #2 is bewildering.

I've touched base with several fellow engine-guys about your issue
This whole thing is bewildering. I’m not a mechanic by trade but I know my way around engines. And the things I’m unable to do to them - either because I don’t have the tool, or don’t possess the know how - I am cool to pay the pros. I appreciate you running my issue by your engine guys. I tried rapping them with a mallet several times but it did not change the outcome.

So I got some cold rolled and made a block off for #2’s exhaust port. It didn’t make a huge difference, maybe 4psi - so up to like 100psi in/84psi out. What it did do, was force the air to escape elsewhere. I could hear a lot of air under the valvecovers. First, I thought, “well it must be the bottom end because the air is coming up thru the oil drains in the head”. But then I got to probing it with my fingers. There is a shit ton of air coming from the top of the valves. I took all the buckets out in anticipation of pulling the head. I made a video and it’s subtle, but you can hear the sound change when I put my fingers over the valve retainers. Don’t pop your eardrums from having the volume up too loud.


So here I am, all but confirming this is shit valve job #2. Because none of the other cylinders leak in this fashion. So now what? Is it the seats? I mean shouldn’t a valve job cover checking all that? I can mainly hear the air on I4 and E3, but there’s air from I3 and E4 as well. I don’t know if it’s crossover from the two main “bad” ones or if they are all leaky.
 

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Show the last shop the proof of the bad job. Tell them to make it right or refund you.
I think fixing it right at this point would be seats and valves and guides and seals. I'd just get it all done so you don't keep having issues. I wouldn't be surprised if there's some issue with a valve being slightly bent or a seat crooked. Best thing to do would be to pressure the shop to replace everything or money back.
 

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I wouldn't be surprised if there's some issue with a valve being slightly bent or a seat crooked. Best thing to do would be to pressure the shop to replace everything or money back.
I was thinking the same, wondering if something is bent or perhaps the face is pitted. But then the shop should have checked it and notified you if that was the case, so i would be contacting them to put the onus on them. Obviously its more inconvenience for you with the shop being far away. If you dont tell them they wont know, so even if you end up having to lap it or something at least they should have had the opportunity to fix the mistake.

I will show my ignorance here but would the stem seals hold much of that kind of pressure? Or are they purely to wipe and keep the oil out?
 

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I was thinking the same, wondering if something is bent or perhaps the face is pitted. But then the shop should have checked it and notified you if that was the case, so i would be contacting them to put the onus on them. Obviously its more inconvenience for you with the shop being far away. If you dont tell them they wont know, so even if you end up having to lap it or something at least they should have had the opportunity to fix the mistake.

I will show my ignorance here but would the stem seals hold much of that kind of pressure? Or are they purely to wipe and keep the oil out?
The valve stem seal is to keep the oil out of the ports in the head they don't seal in the combustion chamber. as to if they would hold the pressure I don't think so that's more the valve guide that should be a friction fit with the valve stem to seal.
 

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The way I see it, you have a few choices:

You probably have air leaking out past the seats, not where the valves are meeting the seat but the backsides of the seats. This is me trying to give the machine shops the benefit of the doubt here.

1. I would try and take it back and have them refund you what they will.

2. lap the valves yourself. First paint the valve seats on the bad cylinder with some Prussian blue compound and run the valve around applying some pressure and see if their valve job is bad or not. If you get a good impression around the valve seat and the valve, I’d probably think something else is going on (see below)

3. Have a different shop or the same shop pull the seats out on that bad cylinder and see if there is any pitting or possibly a defective part of the head that might be missing or something crazy like that allowing air to escape.
 

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Discussion Starter · #119 ·
Thanks guys for the information. Everything everyone has said, echoes what I think. I explained the problem I’d had, how I took it to a shop prior, and still had poor results. No one listens. A place that specializes in JZs should have checked the seats/valves/guides/etc. For what I paid PowerDynamix it should’ve been as good/better than new. So what I am planning on doing, is calling my bank first to see what - if any - recourse I have. I’d take a partial refund even, but if my bank says there’s no chance, then I won’t bother. I’m not real keen on going back to a place that did subpar work. I trusted the shop the first time to do it and now there is no trust. It’s kinda like sending food back to the kitchen at a restaurant. Everybody’s seen Waiting. You know what happens. I guess I had too high of expectations.

My wife has told me that whatever I do next, I HAVE to get it fixed this time, or get rid of the car. She’s over me being in a funk because the car is down, wasting money, and plus she wants the garage to not look like a reject F&F deleted scene. So I am going to do some soulsearching for a good JZ shop.
 

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Thanks guys for the information. Everything everyone has said, echoes what I think. I explained the problem I’d had, how I took it to a shop prior, and still had poor results. No one listens. A place that specializes in JZs should have checked the seats/valves/guides/etc. For what I paid PowerDynamix it should’ve been as good/better than new. So what I am planning on doing, is calling my bank first to see what - if any - recourse I have. I’d take a partial refund even, but if my bank says there’s no chance, then I won’t bother. I’m not real keen on going back to a place that did subpar work. I trusted the shop the first time to do it and now there is no trust. It’s kinda like sending food back to the kitchen at a restaurant. Everybody’s seen Waiting. You know what happens. I guess I had too high of expectations.

My wife has told me that whatever I do next, I HAVE to get it fixed this time, or get rid of the car. She’s over me being in a funk because the car is down, wasting money, and plus she wants the garage to not look like a reject F&F deleted scene. So I am going to do some soulsearching for a good JZ shop.
Or you could get your money back. If you paid with a credit card you should be able to do a charge back id talk to the shops about it though. They just get a new head. If you buy a ready to go head it should be all set and ready to go or you can replace everything on your current head.
 
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