Engine Gods, need some help

joeyd0730 · Jan 23, 2007

so i went to change my oil today and it was the dreaded color. it definately had some antifreeze in it. i will start with a list of engine mods. stock block w deck o-ringed, eagle crank and rods. dss main girdle, speed-pro forged pistons .030, arp main bolts, arp-head studs, e cam, and s-trim@12psi of boost. stock heads ported w/ crane springs and 1.7rr. car was dynoed at 393hp 375ftpds of torque on a mustang dyno with a/f between 11.1-11.7. and 445hp at the wheels on a dynojet with diffrent tune.
Last summer i noticed water in the oil and low oil psi. so i first pulled heads and the head gaskets looked great, also did comp test and numbers were good. so i figured ok, maybee bad intake gasket or something.i swung the motor out dissasembled it and had the block and heads checked for cracks. i was told they were fine and it was probably a bad intake or timing chain cover gasket. i had the motor rebuilt, bearings, rings etc. to me all the gaskets looked fine when i dissasembled the motor but i said maybee its possible. so i got the motor back from the machine shop assembled as a long block with new timing chain cover. all was well until today when i saw the color of the oil. i figure to have only about 800 miles on the motor since rebuild. now my question is, could the block be split? the head gaskets seem fine. maybee the shop never checked it the last time, i dont know. i did notice oil and some anti-freeze on top of the timing chain cover. does it commonly leak here when the block splits? this is all new to me. oil is not leaking down from the intake, it is bone dry where the silicone bead is where the intake mates the heads. so chances are i am going to just get a new block, any recommendations? i will probably be looking for a long block w tfs or afr heads. do i need to have the deck or heads o-ringed? sorry for such a long post. i am just at witts end. thanks in advance, joe
View attachment 408459

Vipersix · Jan 23, 2007

joeyd0730:
Last summer i noticed water in the oil and low oil psi.

What was the last modification done before you discovered this for the first time?

joeyd0730:
i swung the motor out dissasembled it and had the block and heads checked for cracks. i was told they were fine and it was probably a bad intake or timing chain cover gasket.

Which methods were used for checking for cracks?

joeyd0730:
i had the motor rebuilt, bearings, rings etc. to me all the gaskets looked fine when i dissasembled the motor but i said maybee its possible.

They didn't re-use your old gaskets did they?

joeyd0730:
i did notice oil and some anti-freeze on top of the timing chain cover. does it commonly leak here when the block splits?

Check the junctions between the manifold and the block, the manifold and the heads, and timing cover and block. Then check it again. I would recommend stripping all the paint off in this area to ensure nobody missed any cracks or dents.

We'll see from there...

vristang · Jan 23, 2007

maybe the timing cover is cracked???

rockytoohot · Jan 23, 2007

I would check your intake gasket and timing cover gasket. I would also recommend removing the heads and having them and the timing cover checked by a different shop. I would ask other people with engine mods for a machine shop recommendation to make sure the job is done right.

joeyd0730 · Jan 24, 2007

i am not sure how they checked for cracks, i am not very knowledgable when it comes to that stuff. the bloack was not painted when it was checked.
theyused new gaskets, old ones were in my garbage, the junctions between the mainifold, heads are dry as. the timing cover is new,. i will get ot out this weekend and see if i can notice anything, thank for the input

Rick 91GT · Jan 24, 2007

Are you using a MLS style head gasket??

joeyd0730 · Jan 24, 2007

i was told to use the basic stock head gasket with the decked block. i was hoping you would chime in. i am in new york and thinking of bringing my block to you. i think its only like a 4 hr drive from nyc. i cant find a good machine shop around here for the life or me,

Rick 91GT · Jan 25, 2007

joeyd0730 said:
i was told to use the basic stock head gasket with the decked block. i was hoping you would chime in. i am in new york and thinking of bringing my block to you. i think its only like a 4 hr drive from nyc. i cant find a good machine shop around here for the life or me,

Reason I asked is with a MLS gasket you need to put a little silisonce between the head and the deck in 4 places since it doesn;t have the extended tabs and it will leak oil. I am betting the intake lifted or didn't seal, but it could be a head gasket. If you pull the intake off, and pressurerize the coolant system you should see if the gasket leaks becuase you'll get some water drippage in the intake or the head studs.

If I can help let me know

BlownFiveLiter · Jan 25, 2007

Did the machine shop install anything other than the heads? If your cylinders are o-ringed, are the heads, and did you use o-ring gaskets? I'm curious because your first post mentioned it, but your most recent said you had standard gaskets. What type of sealant was used on the head studs? I've heard conflicting arguments regarding putting an extra bead of RTV sealant around water ports on the heads and intake when putting the gaskets on. Some swear by it, others have it leak like a sieve. For what it's worth, my ARP studs were coated with Permatex blue when I installed them into the block and my intake gaskets were installed dry. What torque specs were used when installing the intake, timing cover, and water pump?

joeyd0730 · Jan 26, 2007

i started tearing the motor down today, the block is not the original 91 block, i picked up the current block from a junk yard. i never noticed the threaded hole on the top of the block in the back on pass side. do all mustang blocks have this, or did a build my motor on some junker 302 block thats why i keep having the same problems? thanks again, joe
View attachment 407715

greg251 · Jan 26, 2007

I would look at the timing cover where the water pump goes. They will rot if there are minerals in the coolant and cause coolant to get into the oil. Even a pinhole as soon as it warms up turns into a serious problem. 302 heads crack by under the exhaust ports so that won't be you problem and also get them magnafluxed to look for a crack from a water jacket to a head bolt hole. As far as the silicone on the intake gasket thats more of a chevy thing. Check for straightness on the head and intake surface. If you had the heads milled a lot the intake needs to be milled to match the new angle of the heads otherwise they leak. Also beware of using a cookie to clean up the gaskets , they do havoc to gasket surfaces.

greg251 · Jan 26, 2007

The threaded hole is for a knock sensor which they used in trucks. It's a blind hole so no reason to plug it. Later model blocks seem to all have them but they are not used on the mustangs.

joeyd0730 · Jan 27, 2007

greg251 said:
The threaded hole is for a knock sensor which they used in trucks. It's a blind hole so no reason to plug it. Later model blocks seem to all have them but they are not used on the mustangs.

so the block i built is not a mustang block?

BlownFiveLiter · Jan 27, 2007

I think he was saying that the hole is existent in all of the later model blocks. It could've been used an any number of vehicles that used a 5.0L. I'll throw an example out there for you. My current engine is out of a 2000 Explorer. Well, the shortblock is. The roller block and rotating assembly are the same as were used in the 94-95 Mustangs, so I got one for a steal and swapped it in.

Mr. Rustypwnz · Jan 27, 2007

does it say xxx or yyy on the valley? you def. need to redo the timing cover gasket/waterpump gasket, this time throw a lil rtv on thur to seal it up right. Cause if you have even a little water in the oil, things can go south in a matter of minuites.

joeyd0730 · Jan 27, 2007

i do have the xxx stamp on the valley. i know the heads were milled quite a few times, and the block twice. i am not a machinest so possibly they were taken down to much causing leaks. i usually dap a small amout of silicone around all the water ports on the heads and timng gaskets. i idi notice once i losened the last intake bolt, the intake sprung up by itslef, usually i have to pry them up a little to break them free. almost seemed that the bolts were forcing it to the heads. if the heads and block were milled to much would it cause the intake to spring up when its loosened?

joeyd0730 · Jan 29, 2007

I want to say the heads have been milled about 5 times, and the block once.

greg251 · Jan 29, 2007

You have a problem with the intake then. When you mill the heads and the block everything sits lower. The intake is still at the the same height as stock and it won't seal. Where it sits on the block will be too high and the intake surfaces will be to close to the heads. Defintaly have the intake milled and that will solve your problem.
Take the heads to the machine shop and have them measure the thicknes so they know how much to take off the intake and give them an idea on how much was milled off the block. Thats not good that the intake pops off by itself. Let me know if you have any more questions, I do machine work for a living.

joeyd0730 · Feb 5, 2007

took a good look at things today. seems my intake gasket was the culprit. the water ports line up on the heads, but are a little off on the intake, i dont know why they dont line up on the intake well so that was the water leak, as for the blowby, i noticed in the center of the stock heads there is some kind of exhaust port. well that didnt line up causeing exhaust to blow into the valley causing pressure in the block. i wonder in the intake is casted wrong, everything lines up on the head. anyway i am having rick build me a 331 dart motor with some afr's. so i will get the intake to him to go over things. maybee he can explain what happened. thanks for the help

vristang · Feb 5, 2007

joeyd0730 said:
took a good look at things today. seems my intake gasket was the culprit. the water ports line up on the heads, but are a little off on the intake, i dont know why they dont line up on the intake well so that was the water leak

The reason why...

joeyd0730 said:
I want to say the heads have been milled about 5 times, and the block once.

This causes a mismatch.

If yo are getting new heads, then your problem will go away...

jason

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