how can you tell the difference between blown head or intake gasket?

Asked by Feb 04, 2014 at 05:25 AM about the 1999 Chevrolet Suburban K1500 LT 4WD

Question type: Maintenance & Repair

coolant in oil, milky; runs really rough, no heat, runs hot

18 Answers

20,725

it's hard to as they have the same symptoms. However if your oil is milky then your motor is on borrowed time now anyways. After you take the intake off the heads are just 1 more step, so if your going to do the intake gasket just do the heads as well

8 of 8 people found this helpful.
11,215

1999 suburban. Does it still have the vortec 5.7?? They are known for bad heads. Tell tale sign of heads/head gasket is your coolant system pressuring up as compression pressure escapes from the cylinder into the coolant system.

4 of 4 people found this helpful.
20,725

i have never hear of bad heads on a 5.7 (small block chevy). Now the intake gaskets on the vortecs other hand if you let them get bad enough you can over heat to the point you warp them

9 of 9 people found this helpful.
175

if your oil is milky, you are getting water into the pan via the head gaskets and intake on this motor if one is gone both have to be replaced also check main bearings and rod bearings for scoring if you ran for any period of time, they also may have to be replaced if you ran to long

7 of 7 people found this helpful.
11,215

@Andrew The newer vortec heads '95 and up (w/ the MPFI system) had a weak head design. I've got 3 out of 4 '96-'98 350's with cracked heads right know!! The head gaskets go fairly often. I've only had one intake manifold gasket go? The TBI's though, I've never had a head issue, couple head gaskets but a crap load of intake manifold gaskets. The old sbc's seam to hold up pretty good.

5 of 5 people found this helpful.
11,215

Could be a cold weather thing up here in canada?

2 of 2 people found this helpful.
100

I have a crack in my intank on the top could it be cracked on the bottom to and putting water in the oil

10 of 10 people found this helpful.
11,215

Possibly. Depends on where the crack is, intake runner or coolant passage. It can also indicate that the manifold isn't tightened down square causing the gasket to leak. The manifold should be replaced.

2 of 2 people found this helpful.
1,020

I have a1998 5.7 vortec and water is getting in the exhaust pipes and the oil pan why?

102 of 102 people found this helpful.
310

I have a 1998 suburban w454 and it has a or sounds like a rod knock but my oil isn't milky so what should I do

31 of 31 people found this helpful.
220

water is coming out my exhaust pipe,and my oil top is milky, can this problem be fxed. I have a 97 lincoln town car, high mileage...

22 of 22 people found this helpful.
80

My car runs fine but has water in the oil and oil in the water. But the car RUns fine. No skip or hesitation. Runs warm when water gets low. 97 Chevy lumina 3.1 titer v6. Is head gasket blows or lower in tack bowed.

8 of 8 people found this helpful.
40

most of the time with a blown head gasket u will have oil and water mixed in the pan, and milky substance under the oil cap, along with excessive coolant system pressure which could rupture the radiator , however with lower intake seals leaking on 96-99 chevy 5.7 Vortec, you will normally have an external engine oil/coolant leak, and or mysterious coolant loss with no external leak, which means it is leaking into an intake port and goin into the engine and out the exhaust

3 of 3 people found this helpful.
40

if u already have milky oil, your motor is toast, or soon will be toast, it will need to be disassembled and checked for damage and remachined with new parts as needed, so start thinking of getting a replacement engine and who will do the work, or start looking for a new vehicle.

1 of 1 people found this helpful.
20,725

You've never experienced a lower intake gasket leak on a 5.7 vortec have you? There is almost no way for the coolant to get to the intake ports via the gasket. It almost always is a viable external coolant leak or more common leaks coolant into the crankcase.

1 of 1 people found this helpful.
40

OK Andrew i will take your comment at face value , but why do people have to answer with a smart attitude? Anyway, So As a matter of fact i have one leaking now, no external leak, no extreme coolant system pressure, but it is losing coolant.

40

i will be taking the intake off and replacing gaskets soon, i will know for sure then.

20

what if water in the oil but not milky pulled valve cover off both sides a little moist but not like a head gasket would do took the intake off same as the valve cover a little moister but does have water in oil but not milky never ran hot but once due to bad water pump

2 of 2 people found this helpful.

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