WTF? Do I have engine trouble? Really? Please set me straight.

[TurboBuRick]

Where exactly are the EGR ports on these things? If its before the exhaust valve wouldnt that be in the cumbustion chamber?
Does anyone have a pic of an old head lying around they could snap a pic of to show the EGR ports? I just cant seem to get it straight in my head.

I just stepped out in the garage and took a look. I have it wrong. The EGR ports are in the exhaust chambers. I don't know what I was thinking. Surprised Bison didn't bitch smack me. :tongue:

 

[mtocrs1]

Found out Cylinder two is the one that is leaking the shop air past the exhaust valve. I will perform a leak down test once I get the tester. Can a burnt valve cause a slight engine miss under light throttle?
Also found that the cylinder #4 intake valve tip is rounded on the edges. Like the rocker arm is wearing the valve tip edge?
It takes Cylinder #4 push rod a long time to start flowing oil when engine is running (with valve cover removed). Thinking lifter blead down? It never ends

 

["Reaper"]

You don't even want to know how much money I have in mine.lol It will be all worth it when its running right.:biggrin:

Shaun

 

[bison]

Found out Cylinder two is the one that is leaking the shop air past the exhaust valve. I will perform a leak down test once I get the tester. Can a burnt valve cause a slight engine miss under light throttle?
Also found that the cylinder #4 intake valve tip is rounded on the edges. Like the rocker arm is wearing the valve tip edge?
It takes Cylinder #4 push rod a long time to start flowing oil when engine is running (with valve cover removed). Thinking lifter blead down? It never ends

If the valve was leaking that bad you would hear if while cranking the engine.

 

[mtocrs1]

If the valve was leaking that bad you would hear if while cranking the engine.

You mean if the valve was leaking bad enough to cause the miss under the conditions i described?

 

[bison]

You mean if the valve was leaking bad enough to cause the miss under the conditions i described?

No. I mean when your cranking with the starter and the engine is not running and the engine comes to a compression stoke on that cylinder you will hear it speed up for an instant from the weak cylinder. You would have high leak down there also. I doubt it would cause a miss. There would likely still be enough cyl pressure to get combustion even if it was leaking quite a bit.

 

[pdzz]

Finally had time to make it back to the garage today. So I removed the EGR valve. Next I plugged the hole in the intake that the egr valve is sopposed to seal. No pressure should be getting to crankcase right? Wrong, with the egr hole plugged the shop air is still getting into crankcase. My best guess is that the intake manifold gasket is leaking around the EGR port hole (where intake meets head)? Is this really a problem? Should I tear it down further or forget about it?

OK, I'm going to take one more stab at this. When you put air pressure thru the exhaust system, it goes into the head, ABOVE the exhaust valve. The EGR ports are in the cylinder head, which in turn, can put pressure in the intake via the EGR system. If the engine is running good, I doubt there's an issue. I've never heard of pressurizing the down-pipe or exhaust side, other than trying to find an exhaust leak. I think you're chasing your tail for no reason at all. Phil.

 

[413turbo]

I'll tell you my recent results. i pressure my exhaust side to about 80p.s.i checking for leaks. i always hear some air flow somewhere (my guess is rings) (6 rings x's a small leak in each= pretty big leak).

thanks to another member, i used a smoke machine, just to double check everything. no leaks in exhaust, and smoke never came out anywhere, but with air it sounds like a leak somewhere.
no leaks on intake side either, which i've put about 40p.s.i. from air hose before.
did have small leak on egr diaphram, hope it doesn't hurt anything.

my leak down test came out consistant also.

 

[GNRick]

I have a related question (don't mean to hijack the thread). On my 26,000 mile GN, the blm was 140. I did a smoke test and the only place the smoke came out appeared to be the EGR valve. The valve is probably original. However, I read somewhere that the EGR valve is a metered air leak (or something like that). Is there a rubber diaphragm or something in the valve that could fail from heat and age? Could a bad valve cause a vacuum leak and high blm's? Should I replace the valve?

 

[mtocrs1]

It should not leak past the EGR valve. I would replace. But you can see from my post how much i know.:biggrin:

 

[mtocrs1]

Leakdown Results

Leakdown results are as follows.
Cylinder #2 had 35% leakdown compared to all other cylindes that only had 20-25% leakdown. During the leakdown on Cylinder #2 air could be felt coming out of the downpipe. Something is definatly wrong with cylinder#2 exhaust valve.
I will do a compression test next.
What problems can I run into if I do nothing and continue to run it as is?

 

[TurboBuRick]

Open #2 exhaust valve and let it slam shut a few times. Even turn it. There might be carbon somewhere on the valve getting hung up.

Just a thought.

 

[mtocrs1]

Yeah I smacked it with a dead blow a couple times, no change. I will try to rotate the valve and see if it makes a difference.
Thanks