Got my leak down tester today and tried it out. The only bad thing is the hose to the spark plug hole didn't fit so I made a make shift coupler and connected it to my old compression tester hose. It worked but there was a slight leak in the coupling which I don't know how much it will affect the results. I think minimally but I will get a fitting tomorrow which will totally clear that up.

Anyway, here we go.

I did the first three cylinders twice, #2 is the problem cylinder with the oil leak.

#1 18% leak down, 21% leak down.
#2 35% leak down, 35% leak down.
#3 28% leak down, 31% leak down.

These are hugh numbers as far as I know. I think I should be under 10% and definately be under 15%.

I also got a new compression tester yesterday and last night did a compression on the first two cylinders.

#1 150 psi
#2 150 psi

Which was the same as my mechanic's results.

Any comments on these results? Is it possible it could be head related only (poor leak down)?

BTW, these tests were on a cold engine.


Thanks,

mixing and matching parts will cause leak down testers to be faulty. as for #2 don't sweat my 4.0 has 38% at #1 but has 130 PSI compression.... it is indicitive of a bad valve seat. your next step is to hook your leak down tester back up to #2(this part can seriously be helped out with a stethescope with the amplifier removed(just the open tube)) then open the throttle, disconnect the PCV and listen for noise. then go to the exhaust pipe and listen for noise. then go to the PCV hole and listen for noise. if you get air rushing out your intake then you got an intake valve problem. if you got air comming out your exhaust then you got exhasut valbe problems. if you have air comming out the pcv hole then you have ring problems. if you do get PCV noise before you panick check the other known good cylenders as well. there will always be loss through the rings and learning what normal loss sounds like can be tricky. with how good your compression numbers are i would guess that your valves arn't seating perfectly.

Ok, let me throw this wild idea out there. Before I installed fuel injection I had this funky smell like I was burning rich. I couldn't figure it out, changed out the O2 sensor, etc and couldn't get rid of it. Then when I took the exhaust and intake manifold off I noticed there were a few bolts not used. Not a correct torque down of the exhaust and intake manifolds so when I installed the new intake manifold I made sure to get some studs and make sure the intake and exhaust manifolds were torqued down correctly. So the point here is running rich for several months (6 to 8 or so that I had it, who knows what happend before). Now, couple that with the oil going into the cylinders with the bad valve seals I'm thinking perhaps a carbon build up somewhere that's either causing the valve not to seat properly or clogging an injector.

Anyway, I have a couple of cans of BG 44K coming tomorrow which is suppose to be the cat's meow on carbon clean up. Suppose to dissolve it right up.

This is my next try before I start getting into the engine.

Comments?

i forget did you take the head off?? sometimes you get "coking" on valves that have oil leaks,and improper carb settings. it might be that the coking is starting to interfear with valve action... with the BG44k see if you can get a decarbonizer that is sucked up through the intake and there for through the intake tract and valve. i know that jiffy lube can do that for you, i just made my own metering setup with a main jet and some vacume hose.. it worked pretty good too.

The BG 44K is added to the gas and therefore gets into the valves, cylinder, injectors, etc. One can per tank of gas has done wonders for others I have read about.

http://www.bgprod.com/bgconsumer/bgservices/44k.html

Fingers crossed.

Oh, BTW, I haven't had the head off yet.

<img src="/forums/images/graemlins/drunk.gif" alt="" /> Not to be the pessimist here, but! I have seen snake oil salesmen all of my life. Can somebody here please tell me what it is that can be placed in GASOLINE that will do in very small amounts what the gasoline cannot do? Don't get me wrong here I hope the 44K folks have hit on a NASA invention. I have seen what is clinging to the valve stems with my own eyes and fingers. There ain't no way that a cup of any product in a hundred miles will do anything to that *****. If there was why doesn't EXXON put small amounts of it in their gasoline? Then none of us would ever have this build-up? Maybe I will get an education here, anyone care to try?
Big Jim

berrymans b12 chemtool is good too. put one in the gas and one in the crankcase. run it a hundered miles or so and change the oil...

i dont know so much about removing carbon buildup, as i have not removed the head from my engine, but it did help with dirty carbs and injectors from running cheap gas (if there is such a thing as cheap gas <img src="/forums/images/graemlins/ignore.gif" alt="" /> ) when i ran it in my bronco it puked black smoke everytime i started it for about the first week. then it was all good...ran stronger all around(i know, the buttock-dyno is not scientificly acurate, but i could go much faster and cleaned up the milage issues i was having)

The Buttock-Dyno, Haaa Haaa haaaa.....

That's good.

Anyway, if it can save me from tearing my engine apart it's worth the try.

Bg44k and all those other products are usually used as preventative... once the build up is there.. not much can remove it, but if your lucky... if your vavle is massivly coked then you will need to take the head off and remove the valve and sand blast the coking off. have you hooked up a vacume gauge?? those things are really good for diagnosing valves.

Not what it says on the can, "Provides efficient removal of upper engine deposits".

But then, you are far more experienced than I so I trust your statement.