73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Scaryfastatx on June 14, 2023, 07:51:38 am

Title: Felpro Permatorque Severe duty head gaskets
Post by: Scaryfastatx on June 14, 2023, 07:51:38 am
Anybody ever have problems with these fancy new type gaskets?

https://www.rockauto.com/en/moreinfo.php?pk=447180&cc=1030723&pt=5412

I had a blown head gasket and replaced it with these new MLS looking severe duty head gaskets

Truck ran great a few times. Then when I was changing the transmission fluid/filter it started smoking white again.

I did a leak check on the coolant system and it's dropping from 15 to 13 psi in a matter of minutes...

Thinking these new gaskets had one of those rubber beads give up on me.

Planning on doing a leak down and also see if I'm getting any bubbles at the radiator, sucks so bad. I couldn't wait to get it back on the road
Title: Re: Felpro Permatorque Severe duty head gaskets
Post by: Mr Diesel on June 14, 2023, 08:28:09 am
I dont have any experience with them, but the name of the product makes me assume Felpro just switched their manufacture to China and are trying to foist some new garbage on us with a cool name. I'm skeptical of anything offering a dramatic new improvement like this. I mean, it's a gasket for Pete's sake. What could they possibly invent to significantly improve a piece of paper?

I am interested if anyone else has insight to it.
Title: Re: Felpro Permatorque Severe duty head gaskets
Post by: Shifty on June 14, 2023, 09:38:33 am
I sell/have sold a fair number of them without complaint, mostly to boost/nitrous people, never been told of a failure to date though.
Title: Re: Felpro Permatorque Severe duty head gaskets
Post by: Scaryfastatx on June 14, 2023, 01:52:28 pm
I dont have any experience with them, but the name of the product makes me assume Felpro just switched their manufacture to China and are trying to foist some new garbage on us with a cool name. I'm skeptical of anything offering a dramatic new improvement like this. I mean, it's a gasket for Pete's sake. What could they possibly invent to significantly improve a piece of paper?

I am interested if anyone else has insight to it.

call me a sucker I guess... haha

the real reason I got them, is rockauto had 1 on closeout and since I was just replacing the head gaskets, I figured the thicker gasket with those rubber beads would be more forgiving if my tolerances were looser

I sell/have sold a fair number of them without complaint, mostly to boost/nitrous people, never been told of a failure to date though.

Maybe its operator error here?

From what Felpro told me there is nothing different installing these, vs a standard gasket, so we will see what shakes out
Title: Re: Felpro Permatorque Severe duty head gaskets
Post by: bd on June 14, 2023, 02:08:46 pm
Which transmission is in the truck?  A perforated modulator valve will create white exhaust smoke.

Pressurize the cooling system to ~20 PSI for 30 - 60 minutes, remove the spark plugs, then have an assistant crank the engine over while watching from the front of the motor to see whether a water mist sprays out of a cylinder.  Do your best to identify where the pressure loss occurs before tearing it down.

As long as the sealing surfaces were properly cleaned and verified flat, there are no cracks, and clean head bolts were correctly torqued in three steps using the proper sequence, it is unlikely that the head gasket is leaking.  Have you checked for coolant in the crankcase?
Title: Re: Felpro Permatorque Severe duty head gaskets
Post by: Scaryfastatx on June 14, 2023, 02:47:03 pm
Which transmission is in the truck?  A perforated modulator valve will create white exhaust smoke.

Pressurize the cooling system to ~20 PSI for 30 - 60 minutes, remove the spark plugs, then have an assistant crank the engine over while watching from the front of the motor to see whether a water mist sprays out of a cylinder.  Do your best to identify where the pressure loss occurs before tearing it down.

As long as the sealing surfaces were properly cleaned and verified flat, there are no cracks, and clean head bolts were correctly torqued in three steps using the proper sequence, it is unlikely that the head gasket is leaking.  Have you checked for coolant in the crankcase?

It has the Turbo 350 with the wires in the pan. So it does have the modulator but all the vacuum lines are plugged right now except the one going to the distributor but I'll double check

I haven't checked much outside of doing the pressure test on the radiator. It's been so freaking hot out the past few days
Title: Re: Felpro Permatorque Severe duty head gaskets
Post by: JohnnyPopper on June 15, 2023, 06:31:25 pm
I don't know about wires in a transmission pan,  but a modulator needs non metered vacuum to shift through gears.

If you do have to tear it down again, I would chase the block and bolt threads with a tap and die to make sure the torque isn't compromised.
Title: Re: Felpro Permatorque Severe duty head gaskets
Post by: Scaryfastatx on November 23, 2023, 03:02:31 pm
You guys are gonna laugh

I went back and retorqued the head bolts. It was still smoking. So I pulled the exhaust to see which side was smoking

Guess what? No smoke

I put the y pipe back on... No smoke

Put the cat back on HOLY SMOKE!

New Cat and it's running great!

Thanks for all the ideas guys
Title: Re: Felpro Permatorque Severe duty head gaskets
Post by: JohnnyPopper on November 23, 2023, 04:40:24 pm
A new one!

Thanks for the update... ;D
Title: Re: Felpro Permatorque Severe duty head gaskets
Post by: Shifty on November 27, 2023, 10:15:45 am
Glad you figured it out without getting into the engine proper!
Title: Re: Felpro Permatorque Severe duty head gaskets
Post by: JohnnyPopper on November 27, 2023, 08:05:15 pm
Dodged a serious work bullet... ;)
Title: Re: Felpro Permatorque Severe duty head gaskets
Post by: Scaryfastatx on December 02, 2023, 10:07:27 pm
Yes very very happy and fortunate