'90 F150 4x2 302 EFI. I've heard that one needs to have the intake manifold ground to fit the heads if they are ground at the machine shop. Yea/nay?
But, before I tear into the heads, let me tell you what I see. The intake plenum was wet with anti-freeze, and a little gas. The intake manifold has AF in the dead spaces between the ports and the heads (sitting on top). And this baby was whizzing AF once warmed up, but I couldn't tell exactly from where. The oil dipstick had rust on it, but I couldn't really see any AF in the oil.
So am I looking at a likely blown head gasket (forgot to check compression), trashed valves, etc.?
Engine has 143k on it, but was short-blocked at 93k.
Any comments, questions, concerns, tips, tricks, etc. would be greatly appreciated.
Blown head gasket or manifold gasket, worse would be a crack, you'll likely see where it's coming from once you remove the heads.
Almost there. Still have to disconnect the exhaust manis from the headers (pass side ex mani broken, to top it off...grrrr....), then just pull the heads--all the rocker arms and rods are out already.
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While your cylinder heads are apart, you might consider doing a quick port match and bowl clean-up to gain some ponies.
And a port match and bowl clean-up would be...?? I don't do a whole lot of this, I'm just trying to put this truck in halfway decent running order so that I can sell it. It's already been replaced by a '93 F250 2wd 351 auto 4.10 xcab LB. I sure like the step up in HP/Tq, but that 4.10 is really hitting me in the wallet right now. Once I sell the F150, I'll probably put in a 3.55 and a locker, since it seems to have an open diff.
Not worth doing if your just puttin her on the chopping block. Its porting and polishing that requires a fair amount of elbow grease....better to save a project such as that for a vehicle you want to keep.
Let us know when you find your problem, hopefully its nothing more than a gasket!
You may also have a leak in the TB assembly, where it mounts to the intake...
and with the engine's vacuum it can be pulled down into the upper to lower gasket area...via intake runners and sits there pooling...
this is the only way I can think of coolant getting upstream from where the leaks usually happen.....the intake to head mating surface...
Take the TB off and inspect the gasket surface carefully...you should see some signs of leaks from there.
To answer your question about milling heads, yuo usually don't have to mill
the intake at all if this is the first time milling the heads...
the only exception is that you are taking significant material off the heads...only then do you have to compensate on the intake.
You may also have a leak in the TB assembly, where it mounts to the intake...
and with the engine's vacuum it can be pulled down into the upper to lower gasket area...via intake runners and sits there pooling...
this is the only way I can think of coolant getting upstream from where the leaks usually happen.....the intake to head mating surface...
Take the TB off and inspect the gasket surface carefully...you should see some signs of leaks from there.
To answer your question about milling heads, yuo usually don't have to mill
the intake at all if this is the first time milling the heads...
the only exception is that you are taking significant material off the heads...only then do you have to compensate on the intake.
TB has been off for a few days now. Got the heads off last night, and while the gaskets looked pretty good, there was a small area where the metal was de-laminated from the paper--pretty small and I almost didn't see it.
The intake to head surface sure looked pretty gnarly, though--lots of crud and the gaskets were pretty mushy (not obviously "blown", though), but that could very well have been it.
Anyway, since the heads are off, they're going to the machine shop, probably have a valve job done on them, and I know this is the at least the second time the heads have been off, but I don't know how much they were milled the first time. The first time they were off is because the #8 piston decided to get married to its valves , but only a little bit at a time.
Another Q: I heard once that exhaust manifolds can be welded back together? True or not? I replaced the driver's side one last year, but I'd rather not have to pay another $170 for the pass side manifold if it can indeed be welded. It's broken clean through between #3 and #4, and looks like it was that way for at least a little while (carbon coating on the entire break), but it wasn't noticeable noise-wise like the other one was when it broke.
most cast iron welding used to be done with a welding rod with very high nickle content after heating the item to be welded on. I'm not sure if they have improved much on the welding of cast iron or not. It wasent a very strong weld back in the 70's, anyone had any more recent experience on this may be able to say if it will be an effective repair or not.
i use M + R alloys 800 series rods and they are the best i have used. they seem to be stronger than the original base metal with no side effects. i've welded evrything from manifolds to trannies with this wonder series of rods. they're not cheap but you get what you pay for
TeulonF250, these rods work on cast iron or just steel? Do you have to preheat the cast iron as with nickle rods? Sounds like it might be the ticket if it works on cast iron.
Grrrr....just got a call from the machinist--BOTH heads were cracked. At least that explains all the coolant leaking out (and probably both exhaust manifolds cracking in two over the past year or so).
Of course, now I have visions of custom work dancing in my head (no pun--), but I'd better just fix it and sell it so that I don't end up sleeping in it.
hummm...if you kept it, ate mac and cheese for awile, aluminum heads, headers...hummm
I'd be sleeping in it because SWMBO would make me....she's already not too happy about the ~$700 I'm gonna have in it after I'm done. (At least I got a decent torque wrench out of it ).
, but only a little bit at a time.
), but I'd better just fix it and sell it so that I don't end up sleeping in it.
).
