Exhaust valve condition. Look good ?

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candymancan
Posts: 3652
Joined: Tue Mar 22, 2016 11:32 pm

Exhaust valve condition. Look good ?

Post by candymancan »

So i got a bore scope. 5mp pretty good wuality honestly im surpised for 40$.

So what do you think of my exhaust valves. I couldnt get 7 or 8 jist too tight of an angle.

But here is 2 4 6 in order then 1 3 5. One looks oily so i guess im burning oil on that side ? One looks like it has metal on top of the valve.. i think it might be from the manifold gasket which broke apart there..

Hopefully it blows out versus getting in the cylinder. Thinking of trying to get my magnet snake in there ? But maybe ill knock it down. So what do you think ? Let it blow it out ?

Changing my spark plugs too so ima get some pics of the pistons too later. Hopefully all is good
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1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)
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tgreese
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Joined: Fri Jun 08, 2012 6:31 am
Location: Medford MA USA

Re: Exhaust valve condition. Look good ?

Post by tgreese »

Mmm. Unless there's a obvious notch in the valve perimeter, you can't tell much by inspection. Compression test, wet and dry, or much better a leakdown test, will tell you more. Air escaping via the exhaust is a clear failure, or compare pressure you maintain cylinder to cylinder.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
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Topic author
candymancan
Posts: 3652
Joined: Tue Mar 22, 2016 11:32 pm

Re: Exhaust valve condition. Look good ?

Post by candymancan »

Ok its all back together.... to people who suggested using a copper exhaust manifold gasket... fu.. lol. It leaks everywhere ob the passenger side. All the ports..

Knew i shoulda gotten the other ones.. now i gatta take this nightmare apart again.. bolts are extremely tight too.. tighter than id want then to be.. . God dangit.


Drivers side seems fine.. but the flange now leaks. Passenger side gasket leaks though.. but once warmed up it mostly goes away.. still ticks on port 2 though but overall the engine is quieter..

Still sucks it leaks though.

I did notice these amc heads could use a good porting.. there is so much material on the bottom that could be taken off around the gaskets etc. Maybe down the far road when i rebuild this engine haha
Last edited by candymancan on Sun Mar 12, 2023 3:52 pm, edited 1 time in total.
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)

letank
Posts: 4010
Joined: Wed Oct 03, 2012 9:16 pm
Location: SF bay area

Re: Exhaust valve condition. Look good ?

Post by letank »

candymancan wrote: Sat Mar 11, 2023 6:09 pm Ok its all back together.... to people who suggested using a copper exhaust manifold gasket... fu.. lol. It leaks everywhere ob the passenger side. All the ports..

Knew i shoulda gotten the other ones.. now i gatta take this nightmare apart again.. bolts are extremely tight too.. tighter than id want then to be.. . God dangit.


Drivers side seems fine.. but the flange now leaks. Passenger side gasket leaks though.. but once warmed up it mostly goes away.. still ticks on port 2 though but overall the engine is quieter..

Still sucks it leaks though
For sure a big bummer, may be your exhaust manifold is out of shape, check its plane level.

I used the copper on the 85, and it was really good, I had to retorque a few times withing 6 months of installation... and may be a few years latter, it has been over 10 years since the installation.

Also check for cracks in the manifold. I had to do mine because one side had a big crack.

Otherwise these valves look good... a bit oily but not a debacle.

BTW which scope did you get... ? mine is terrible, it has no depth of field
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)

Topic author
candymancan
Posts: 3652
Joined: Tue Mar 22, 2016 11:32 pm

Re: Exhaust valve condition. Look good ?

Post by candymancan »

Ya two look oily.. not sure why.. the spark plugs looked fine. But one did have carbon build up. Might be burning oil slightly.

Here is the scope i bought.. its wireless too goes right to my phone really nice picture quality.

As for my gasket.. it seals up when engine is warm.. drivers side is sealed.. but passenger leaks on port 2.. but its 90% better thsn prior.. engine is so quiet now its amazing how noisy it was prior. I dont mean ticking but just overall noise.. i didnt realize it was leaking exhaust.

Ill snap pics of my postons soon. I wonder if i can snake this scope through the carb to check the intake valves ? Or would i need to remove the carb




https://www.amazon.com/gp/aw/d/B07MV6X4 ... asin_title
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)

sierrablue
Posts: 1208
Joined: Wed Nov 30, 2022 8:02 pm
Location: MN/CO

Re: Exhaust valve condition. Look good ?

Post by sierrablue »

Did you get all your concrete off the heads? As letank said, it sounds like the surfaces aren't smooth.

On my dad's truck, they need tightened up every once in awhile, but if you tighten them back down, it goes quiet again. But if it's totally messed up (either side of it), it's going to leak.
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
-Front shoulder belts (rears eventually)

viewtopic.php?t=23070

There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.

letank
Posts: 4010
Joined: Wed Oct 03, 2012 9:16 pm
Location: SF bay area

Re: Exhaust valve condition. Look good ?

Post by letank »

thank you for the borescope link
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)

Topic author
candymancan
Posts: 3652
Joined: Tue Mar 22, 2016 11:32 pm

Re: Exhaust valve condition. Look good ?

Post by candymancan »

sierrablue wrote: Sun Mar 12, 2023 7:40 pm Did you get all your concrete off the heads? As letank said, it sounds like the surfaces aren't smooth.

On my dad's truck, they need tightened up every once in awhile, but if you tighten them back down, it goes quiet again. But if it's totally messed up (either side of it), it's going to leak.

Yea i did haha.. i know its silly concrete.. but it worked i BEEP you not lol. But ya this leak is port 2 where its leaked for 6 yesrs.. so msybe it is uneven there.

Damn.

But 90% of the other leaks are gone at least so copper did work.. just not 100%.

I was worried about how tigjt i made the bolts too.. i made em very tight.. 18ft lbs i think it spec ( like you can get a torque wrench on this) but i probly made em to 30 at least using a small socket erench. Oddly two days later i tried to losen em in fear they were too tight.. and they were already losened. So i guess ill just keep tightening just not gorilla anymore.

I ordered those squishy gaskets i forgot the name. That others suggested.. Ill stick with copper fir now and see if it self seals from heat cycles and tightening.

If not i guess ill redo the passenger side with those other gaskets.. drivers is fine with copper. Of course the flange there leaks now from me moving the manifold. But i ordered some high temp rtv for thag.. 650f. I doubt the flange gets that hot considering it uses rubber for the gasket to begin with.


Its insane how quiet my engine is now though... at idle i heared no ticking.. just engine obviously.. but after these copper gaskets.. the engine is way way quieter.. so i must have had exhaust leaks everywhere
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)

sierrablue
Posts: 1208
Joined: Wed Nov 30, 2022 8:02 pm
Location: MN/CO

Re: Exhaust valve condition. Look good ?

Post by sierrablue »

You might try using some fine sand paper on there if/when you take it off again. Just try and level things out a little bit, on both sides.
'71 Wagoneer (DD)
-B350 (HEI, iron 4-barrel, Edelbrock 1406), TH400, D20
-'74 D44 front (nonpower discs)
-custom headliner
-Front shoulder belts (rears eventually)

viewtopic.php?t=23070

There are 2 major differences between new Wranglers and FSJs. FSJs are meant to be both utilitarian and capable, not just capable. FSJs are also rarely initially recognized as Jeeps by the average American.
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