5.7L engine with coolant in the oil

this is for 98 with 5.7L

I fixed intake manifold gasket leak at 50,000 miles.
2 years later, with 77,000 miles, coolant began disappearing.
I found coolant mixed in the oil on th dipstick.

Yesterday I pulled the intake manifold. It is covered with light brown sludge (oil and coolant recipe). The engine was running fine and we did not drive it much when the coolant started disappearing. So I'm going to replace the intake manifold gasket again. But first I have to figure out how to get all that sludge out of the engine.

I read some shops have engine oil flushing machines that would clean all this crud out.

Or I could try one of those flush products you run in the crankcase for 5 mins.

Anyone have any experience with removing coolant contaminated oil?

this is for 98 with 5.7L

I fixed intake manifold gasket leak at 50,000 miles.
2 years later, with 77,000 miles, coolant began disappearing.
I found coolant mixed in the oil on th dipstick.

Yesterday I pulled the intake manifold. It is covered with light brown sludge (oil and coolant recipe). The engine was running fine and we did not drive it much when the coolant started disappearing. So I'm going to replace the intake manifold gasket again. But first I have to figure out how to get all that sludge out of the engine.

I read some shops have engine oil flushing machines that would clean all this crud out.

Or I could try one of those flush products you run in the crankcase for 5 mins.

Anyone have any experience with removing coolant contaminated oil?

http://www.fullsizechevy.com/forums/showthread.php?t=176888&page=4&pp=20

Read the tread at that link!!!!
There are several types of gaskets... Don't let anyone fool you. You want the one from GM that has metal inserts were the bolts go so that you do not over torque the bolts. And it keeps the plastic from getting crushed from the expansion and contraction with heat and cold. I used felpro and I am sure I will be in the same boat as you, and have to change them again.

As far as the gunk in the engine. My first and hardest advice is to pull the oil pan. Clean it with b-12 chemtool and with the intake removed spray down the lifter valley.

The half a$$ way would be to plug the oil drain holes in the lifter valley and get to cleaning with anything you can... screwdrivers, towels, compressed air... ect. till you get the gunk out. When you get it to the point that it is film and not chunks of crud. Hose it down with b-12 and let it go into the pan... change the oil... run it for a 100 or so miles... use a can of chemtool as directed for crankcase. and change oil again.

Hope this helps... good luck!!!

Head Gasket

http://www.fullsizechevy.com/forums/showthread.php?t=176888&page=4&pp=20

Read the tread at that link!!!!
There are several types of gaskets...

I went to the dealer and got the plastic gaskets WITH the aluminum tabs. I can see they changed the seal design. $57 for two gaskets, nothing else.

Next, I stopped by the Oreilly store and asked to see the gaskets. I was shown the ones I'm familiar with from my previous repair. I asked if there was a new design "perma dry". I was shown the Fel-Pro perma dry version that looks similar to GM original. It has the Tabs (basically spacers) and some silver paint but looks like the actual seal tracers are also redesigned. For the about the same price of $59 the Fel-Pro includes the entire gasket set.

Still, all the other seals are so recent and look to be in good shape. There is no way to tell if the Fel-Pro's are identical and same manufacturer or not. I suspect they are because some company makes the GM gaskets for GM so it may be Fel-Pro.

I asked why they don't make them completely out of aluminum. The guy showed me similar gaskets for the V6 which are.


Thanks for the help

Head Gasket

why do you say this? If the head gasket was leaking at the rate I was losing coolant into the lifter valley, I would have noticed performance drop and overheating, based on what else I've learned. I'm not saying no, but could you explain based on your own experience?

I had a similar issue or so I thought. I had a 305 that was loosing coolant. So I change the intake gasket thinking that it was the issue. For some stupid reason I seemed to work for a while. However I have just replaced the 305 with a 350. I took the heads off just to start rebiulding the 305 and found that the head gasket was the original problem. So I would speculate that you may have a head gasket issue. The sludge your talking about , I found that adding about 1 cup of trany fluid to the crank case help clean the sludge out. But I ALSO ONLY RAN THE MOTOR WITH THE TRANNY FLUID IN IT for onlt a couple days. Good luck

what would gm merlin do? Merlin, you still moderate?

You might do a little research on LubriClean. I'm not sure what it's supposed to do but the construction company I work for puts 8 oz. in the oil everytime the oil is changed and they continually get 300,000 + miles out of GM 1/2 and 3/4 ton trucks.

James

what would gm merlin do? Merlin, you still moderate?
W.W.M.D. :dunno: :iceslolan

What would merlin do?

Run like hell :evillol:

When I have a vehicle with coolant in the oil, I vacum the majority of the sludge with a shop vac. then clean the engine valley with a brake cleaner type product to get the remainer out.
Then drain the oil.
The problem is the coolant has already attacked the bearings..hopefully the damage is minimal.
You can try having an engine flush.

You might do a little research on LubriClean. I'm not sure what it's supposed to do but the construction company I work for puts 8 oz. in the oil everytime the oil is changed and they continually get 300,000 + miles out of GM 1/2 and 3/4 ton trucks.

James

searched the web for "lubriclean" and "lubri-clean" found nothing

what kind of coolant are you using? the orange dexcool or the green. if you are using the dexcool i would convert the truck over to the old style green coolant, not the green that you can mix with any kind of coolant. type in dexcool complaints in you search window and it will take you to sites that have thousands of complaints about the dexcool coolant. with dexcool if you let the coolant get low or air enters the system the coolant reacts with the air in the system and it turns to a brown sludge. i had the problem on my 97 2500. ive also read that the dexcool eats at the plastic on the intake gaskets and eats at the head gaskets. i replaced the intake gaskets 3 times in 120000 miles before i found out about the dexcool problems. also when you bolt the intake down use lockwashers or blue loctite or both.

if you convert from dexcool to the old style green you have to flush out your entire system because if you mix the two i read it starts to gel up