engine knock after top end rebuild | Page 3 | Ford Explorer Forums - Serious Explorations

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engine knock after top end rebuild

yep they all move freely. jusst finished cleaning the mating surfaces and im about to put the heads back on. i loosened all the exhaust manifold bolts and re torqued them and the spark plugs. got to wait till 730 to get the valve and lower intake gaskets.

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You know you need to tq the heads and lim at the same time right?

It is possible but not typically in a engine, the springs usually have enough force to push it down.even if it does it should act like a solid lifter.the max spec on the lifter plus the rod should still allow the valve to close.it shouldnt make noise if so, it when they get stuck down and the rocker smacks the valve. One thing maybe to check is that the lifter moves freely in the bore.I have seen them be very tight and will smack the cam after the top of the lobe

This can happen especially if you don't mark the lifters and put them in the wrong location upon reassembly. It happened with me. Sounds like it could be the case here. Further, perhaps you have this or not, but it still sounds like a lifter that is not working right. Maybe it is not fully collapsed so it doesn't yield when pushed upon, but when the engine runs, it makes the noise you hear.

Still leaning towards oil seeping past the valve covers and dripping on the exhaust as the cause for the smoke, but even that is a stretch considering having that happen to my headers, I did not have any smoke like described and my leak was quite substantial. Loose LIM bolts could also leak oil, trouble is you should also leak coolant or at least leak between cylinders. Have you checked for oil in coolant or coolant in the oil?


this is from the passenger side head. a little carbonization. thats not oil, and i wiped it off.

drivers side head. still looks brand new.

this is the difference in the gaskets. the thick one is the fel pro one i took off. the skinnier one is the titan engines gasket. the rtv is about half as wide, but if you look closely, every single passageway has its own border. the fel pro one has one single outline. so, i think its a tradeoff. i have to use the titan engines one because i cant afford to get another one.

this was the block once i took off the heads and the gaskets. pretty clean, nothing in the cylinder bores.

mahones: i didnt mark the lifters but i did them one by one and put each cleaned lifter back when i was done. as they sit now, theres no way to know which lifters are bad. they all look good, and none had any pplay when i checked to see if the rocker arms would depress.

the number one cylinder had a lifter i broke so i had to get a new one.i primed it the same way as the rest, but maybe by putting a new one in with the old one it created an imbalance. would it be a good i dea to replace the other lifter with a new one on the first cylinder to keep it homogenous?

also yes, i followed the manual and torqued the LIM and heads down in sequence.

another question: i was informed that when i put the manifold on, i should fire it up that same day. but it take about 24 hours for the rtv to cure... does that matter? it takes 20 mins for it to set, but 24 hours for it to fully cure.

Technically you need to finger tighten it for an hour then tq it down(lim).also the heads you should wait 15 mins after second tq sequence before turn the final 90*

i will do that. hopefully ill get this thing back together and there wont be any problems. its going much faster on the rebuild 2x.

Im wishing you good luck..this really has baffled me..

are you guys using rtv on the whole valve cover gasket or just on the seams?

Just where it mets the intake..I use a film of rtv all over the lim tho and globes on each end of the lim

do you think its a good idea to match the new lifter on cylinder one with another new one or let the old one have another try?

well i put the drivers side head on... then i heard something metallic rattle. i took the head off and shook it around for a little while and...



i doubt this is what the knocking sound was from but either way im glad i got this thing out of the head. i dont think it was in there when i put the head on... i think it might have been pumped in from the block, like a nasty piece that came loose when there was a full force flow and full compression. it looks like slag or something

Wtf!!!! Who makes those heads?? Doubt that was your problem also but that makes me wonder about the heads PERIOD....did you have them tested at all or just went for it?? I've had a set of bad heads before, threads on here..:(

Wait a minute what style are those heads and what year pistons are you running??those to me look like 98tm heads and 90tm pistons. .

Those are 98tm..didnt see you mention that anywhere unless I missed it..is those 90-94pistons??now I need more details. ..obviously they are marked ""late model"" now I look back but could tell from the CC

Also specifically which hole did that chunk come out of??you know one on those is the oil passage way

they are supposed to be 93 tm heads, thats what i bought from the ebay listing. they are from titan engines and came with a whole gasket set. they came pre loaded... ill find some more inclusive pics of the head... i really hope these are not the wrong heads. they say "late model" in sharpie on them. i went through the whole do these match your car directory on ebay... it wont let you buy them if the auto part doesnt match the car you have on file.

that said, you would def initely know more what heads these are than me or ebay

the car is a 94 explorer xlt bone stock.

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