I have a leak in the front of my engine. If you look at the coolant temp sensor look right and down an inch all the way towards the block. I can't tell if this is the edge of the intake or a hole in a aluminum casting...
96 4.0L


Dick

 

Dick,
Leaking oil or coolant?

 

Coolant! The green stuff

 

dick,
can you post a picture?

must be the lower intake manifold to head seal or water pump seal to timing cover?

my lower intake manifold gaskets were well ate up by ?coolant?, had to replace last year. even some corrosion in the cast intake manifold coolant jacket ports. heater hose steel nipple corroded.

i'm going to throw a zinc bar inside past the thermostat the next change if it doesn't look any better inside.

guess Ford has found the new designed obsolescence

there are Chev SB V8 blocks on the road now that are 50 years old. if we can't find a way to stop this coolant corrosion ours aren't going to make it past 20


cliff

 

You have to use silica free coolant just like my olds vw van..I looked at my green van in the garage and it looks to be where the intake meets the head.. I'll see if I can get a good pic with macro on my S3IS canon...So whats the best stop leak? Seems there's some in my wifey's van hasn't hurt it any seems to be the kind that has fibers. Long something or other I noticed when I took the cap off..


Dick

 

Anyone have a tutorial for taking apart a 4.0l? Pic's

 

they make some krap with plant fibers from the gold seal plant. GM had to use it in their Cadilliac NoStars engines several years ago because the head gaskets leaked like the Space Shuttle booster O rings.

no worth the time to put in. i tried the garbage in my Aero. plugged the leak for awhile but what a godoffal mess to clean out. still think the heater cores are partially plugged.

i've been using the silica free ahtifreeze as long as it's been avail on the retail shelf and even before that when i got it from the local comm. Cummins and CAT dealers. don't know what the Aero had in it when new but have changed every 2 years, now going to yearly changes. Cheaper and easier than gasket jobs.

haven't seen any good online tutorials for working on the 4L OHV. took me about a week but I'm old, slow and can't let work interfere with fishing and beer drinking.
use both Chiltons and Haynes, enough photo angles between the 2

i had problems getting the fuel rail to seal to the top of the injectors, had some corrosion in the fuel rail holes. see my fix in my previous writeup.

get the FelPro upgrade Premium intake gasket set with the 2 separate intake left and right manifold gaskets rather than the flacky OEM Ford style one piece that goes across the upper crankcase valley. use Permatex "Right Stuff" sealant.

i did a write up on my IM gasket replacement a couple years ago. no photos. requires a female Torx about 8mm for intake manifold long bolts

wear mech. gloves and save the red stuff for the Red Cross

 

I'm gonna get the gm seal tabs lots of good right ups about them. They don't clog anything and only do their work when there is a leak..If they work good if they don't I will have to do the yob....tanks.


Dick

 

Seal tabs from the gm dealer.5 dollars for 5 does two vans, The dealer said these things are great never had an issue been using them for years as do all GM dealers. I crushed 3 put them in and 15 mins later no leak...We'll see...I'm gonna put some in my wifes van also as the coolant drops alittle...I saw an article that said to use them when rebuilding a new engine, just put a tablet into each head etc...no reason not to..also neat ingredients Ginger and almond shells go figure..


Dick

 

The seal tabs are a temporary fix. The cause of the problem is corrosion eating away at the mating surface between the intake manifold and the head, usually at cylinder 1 (front passenger side). The longer you leave it, the worse it gets. The problem is so common that the Fel-Pro gasket kit includes a little note about it. If it's bad, it will require weld-filling and machining. If it's not bad, you can get away with putting some grey RTV in that area. The grey stuff has more structural strength than other, so it can better stand up to the pressures in that area.

I think I wrote up my experience replacing the manifold gasket set a couple years ago as well. It took me about half a day to remove everything and clean things up to prepare for installing the new gaskets. I left the fuel rail bolted to the lower manifold, so I did not have to worry about resealing fuel injectors and such. In fact, I was able to leave the wiring harness, including those for the injectors, on the lower manifold, once I disconnected it from the two big connectors hanging in the middle of the hood opening. One thing that bit me on my 90 model is the PCV valve; its plastic body broke as I tried to pull it from the upper plenum. I epoxied it back together.

The other thing was on assembly, there is a 3-step torque sequence for the lower manifold bolts and nuts. You should run your torque wrench through each fastener a couple of times at each step to make sure that they are indeed stabilized at that torque spec before moving up to the next step.

 

From what I read they might be a permanent fix. With 150k on the engine I think I'll use these till the cows come home...HMM I don't have any cows..You get the picture. Online they were using them when building a brand new LT1 engine...Thats good enough for me.
Thanks for the pointers..

Dick