1997 blazer intake replacement please help

engines
oil
repair
used
leaks

#1

please help me out… i recently replaced my lower intake gaskets, left and right. i can get the vehicle to start,but the coolant is INSTANTLY going into the oil. and i mean INSTANTLY. i cant fill the radiator. did i crack the block or blow the head gasket? or does it sound like something didnt get sealed right? 97 blazer with a 4.3 vortec engine. please help thank you.


#2

Did you apply a thread sealant to the threads of the lower intake manifold bolts?

Tester


#3

If everything coolant-wise was ok before the intake manifold gasket change, then something probably went way wrong with the install. The coolant passes through the intake to crossover in the front and rear. If the seal did not seat right, coolant pours straight into the crankcase. At the very least, the intake needs to come back off.


#4

honestly i didnt know anything about sealing the bolts. can you explain this in more detail pleaseee?


#5

pl thank you busted knuckles. in your opinion do you think i messed up anything on the install?like, damged the head, etc?


#6

That SHOULD have been in the install guide and the repair manual. You do have a repair manual, right? At the very least, you need the manual for the bolt tightening sequence and torque specs.


#7

yes sir and i followed the manual precisely… but it said nothing about sealing the bolts?


#8

The lower intake manifold bolts thread into the heads where water jackets for the heads are located. If a sealant isn’t applied to the lower intake manifold bolts, coolant can leak past the threads on the bolts and leak into the engine.

The sealant also acts as a lubricant so the proper wet torque of manifold bolts is achieved.

Tester


#9

thank you tester. now, will this leak be slow or fast? cause i literally could not fill the radiator. the coolant was draining that fast


#10

Unless you heard a snap or pop, chances are the intake manifold gasket slide out of place before the intake was bolted down.


#11

when i took it apart again, gasket was still in place.


#12

Does the engine have the plastic upper intake manifold?

Tester


#13

yes tester the upper is indeed plastic


#14

Then what you want to check is if the port in the upper intake manifold for the EGR gasses has eroded away.

http://www.dormanproducts.com/documents4rb/Intake%20TechSpeak.pdf

There’s coolant jackets around this port that’s supposed to prevent the plastic from eroding away. But the original GM design was weak in this area. So Dorman redesigned these intake manifolds to eliminate the problem.

Tester


#15

@settersj19‌

Did you use new intake bolts? I highly recommend it

I would use AC Delco parts, or at least Felpro

Was the intake and head extremely pitted?

Did you get very aggressive when you were cleaning off the old gasket material?

What did you use to clean off the old gasket material?

Did you use a torque wrench and proper sequence?


#16

i used felpro. i also used the old intake bolts.used the torque wrench, followed torque specs.my problem is, its not just leaking now.its pouring. like,fast. instantly into the oil.


#17

tester, if the port was eroded, wouldnt i have noticed this before the intake change?


#18

If the coolant is literally pouring into the oil as you describe, and you didn’t have this problem before, I think something has gone sideways, backwards, or upside down with your gasket/intake installation. Are you 100% certain the gasket is located and seated properly? Can you take and post a pic of the gaskets as they lay on the head, and of the sealing side of the intake?


#19

Okay.

Remove both valve covers. And try slightly tightening the head bolts to see if one has broken.

I’ve only seen it happen once on this GM engine. So if it’s happened once, it can happen again.

Tester


#20

Okay.

Remove both valve covers. And try slightly tightening the head bolts to see if one has broken.

I’ve only seen it happen once on this GM engine. So if it’s happened once, it can happen again.

Tester