1996 3.1L intake manifold help

[AimFire]

I need advice on repairing the intake manifold gasket for a 1996 3.1L Lumina with 141K miles. I’ve been subject to mechanics and dealers lying to my face and trying to rip me off – I’m a woman and I look like I’m about 18 so people assume all I can do is put a key in the ignition.

Late March I noticed a problem with the water pump after the overflow tank would leak a full coolant tank after a week of driving so I had the water pump, thermostat and serpentine belt replaced last Monday. I was in VA this Monday when a light started flashing on the dash so I stopped at a gas station. The oil was high on the dipstick and the overflow coolant tank was sludgy (like a septic tank) and below the cold fill line. The oil and cap aren’t milky so I don’t think coolant is going into the oil but it’s definitely getting into the cooling system.

I can’t pay to replace the motor so to be safe I had the Lumina towed to the nearest repair shop. I just got the estimate today ($1100) and that shop is lying to me about repairs I need and trying to charge me 2 or 3 different times for the same service. Oil and filter was on it 2x, coolant 3x, apparently my belt was “frayed and pitted” and the water pump mounting gasket was leaking. The back pedaling when I mentioned last week’s repairs and the double charges was amazing!

I’m considering trailering the car to PA since the shop I normally use is saying <$650 for the intake manifold gasket, coolant flush, and oil change. However, my dad was telling me about a liquid sealant that could be used to seal cracked gaskets…How do you know when it’s completely sealed or if the gasket is too far gone for a sealant like Bar’s Block Sealer?

[kevinb70]

no, leak fix isnt going to help cracked and failing LIM gasket. the gaps are going to be too wide for leakfix.

see my recent thread "top end rebuild" basically same L82 3.1L engine as yours. my 2nd LIM replacement - the first replacement (@83k) was plastic like the original and cracked. I'm now at 184k.

i went 1 step further and I pulled the heads (head and exhaust gaskets + new head bolts are only $70-80 more), took them to have a machine shop rebuild them, mailed injectors off for rebuild (flow sheet I got back with it said they definitely needed cleaning).

shop charged $150 to rebuild the heads, $25 for upper/lower manifold cleaning. injector service was right at $100 total for all 6 injectors. spent about $370 in gaskets, hoses, etc from rockauto.com.


gonna put a high emphasis on not driving the car much if you wind up with coolant in the oil (will look like a chocolate shake) as its very bad for the bearings.

I took pics of the old LIM gasket and headgaskets, give you an idea of what you're dealing with.

She's running like an absolute dream now, just as quiet as she was when new. Are you getting any ticking sound from the engine, esp when cold? that's the sludge causing lifters to stick... had that real bad before i took her apart.

[AimFire]

I did see the post about your '98 - the problem is I need the car to get to work and am a full-time student so I have no garage, no tools, and no time to do it myself. I don't want drive it back up the interstate so trailer it to PA and fix it here? .

Discovered the same nasty sludge in the radiator when a family member returned the car after 6 months and said the heat wasn't working. Dealer she asked wanted $200 for a new thermostat but the reservoir was dry so I figured it was a bubble in the thermostat housing. $10 for a gallon of coolant and a day later it was fixed. Had the system flushed out when the leaky pump was changed.

Adding the coolant is when I saw the 'chocolate shake' in the radiator so I'll try to post a pic if I can find it. At the point I left the car on Monday, there was no coolant in the oil but the coolant overflow was nasty brown like that again.


No problems with ticking sounds but I do know that I need to replace the spark plugs and wires soon. They're original and every couple months it 'lugs' when I accelerate slowly but hard acceleration fixes it. I think that's due to a cylinder missing occasionally but that may be a summer project.

[kevinb70]

you may not have any oil in the coolant.

the sludge is caused by DexCrud, i mean DexCool coming in contact with air. I will not run dexcool anymore... i am using NAPA plain green antifreeze.... hard to find now that everything is "universally compatible" antifreeze, a close cousin to DexCrud.

[AimFire]

These 2 cell phone pics are from under the radiator pressure cap and hard to see but taken when the first dry reservoir/heating problem was noticed. It's sticking to the walls as far as I could see in and was the same color/consistency as what I'm seeing in the overflow tank now, even after a new water pump and coolant flush.

Yeah, may not have oil in the coolant *yet* but it's too hard for me to speculate when the car is 300 miles away! I'll know more by Monday at the latest.

[kevinb70]

that may only be DexCool sludge, without oil.

Air + Dexcool = sludge + corrosion. Which simply means you have air leaking into the cooling system (gasket, hose, radiator, bad rad cap, etc...)

I didn't see any trace of an oil film floating on top at the filler neck. That is what you need to look for.

Smell for scent of coolant at the tailpipe - coolant leaking into your air intake passages thru LIM gasket

Smell of exhaust/gas in antifreeze - head gasket leak

Oil film in radiator - LIM leak between coolant and oil return passage. When engine cools, there is a suction force which 1) sucks water from reservoir into radiator due to contraction of cooling system while cooling 2) will suck any oil in contact with leaky gasket right into the cooling system - which should also result in coolant getting into the oil when the engine is running and hot - coolant is pressurized and will force its way into the oil return passages in the head

Being you have no coolant in the oil, you may be lucky in not having a LIM gasket failure at this time.


as far as the 2x oil change - lets just say after my LIM repair, I have done about 3 oil changes to be on safe side - but i had coolant in the oil

and the 3x flush.... i have filled and drained my cooling system 4-5 times and it's still very dirty. That 3x may refer to "3 gallons" of antifreeze


I'll go thru my pics for one showing how oil looks when mixed with dexcool sludge

[Bearwulf]

If you want to do a good job of cleaning out the cooling system, install a flushing tee in heater hose, flush back thru radiator until clear, use 1-2 tbsp. crystal drano (install @ tee), fill with water run engine for 10-15 minutes after thermostat opens with system closed. Drain by carefully opening flush tee to relieve pressure, then run clear water from hose into tee into engine to remove drano, allowing system to drain from filler neck & draincock. Close draincock after 10 min., remove hose repeat closed system warm-up & drain procedure, remember to introduce cool water slowly into hot cooling system, as adding it fast could crack block, manifold etc. This Should remove all contaminant from cooling system. Then refill with A/F & water mix (70% my recommendation).