90 ZR1: Oh crud, did I break it? - Page 3 - ZR-1 Net Registry Forums

Jagdpanzer · 11-26-2010

You might try looking up Jim Milstead known on here as "TheLurker"
He's from the Dallas area and knows the ZR-1 & LT5 as well as anybody and a great guy. I'm sure he can direct you to a competent local shop.

GTOger · 11-26-2010

Well, I wasn't able to get with "The Guy" at the shop today due to it being a holiday weekend and all. Same story at Corey Henderson's shop down in New Braunfels. So I'm going to have to try and exercise a little patience. The tech I talked to at Corvettes of Dallas (now Corvette World as of a couple weeks ago) says he's never broken down an LT5. He's never heard of one blowing a gasket like this. (Perfect... leave it to me).

He did mention that in order to get at the heads and pull the thing apart it could be necessary to pull the engine out of the car. That doesn't sound like any bit of fun. It sounds like a whole lot of money. Anybody have any words for me? I'm starting to get a little scared. A $10k engine rebuild is not within my realm of possibilities.

Z51JEFF · 11-26-2010

Replacing the plugs are fairly easy but #8 can be a challenge.What works for me,a telescoping magnet,2 inch 3/8 extension and a 3/8 ratchet with a pivoting head.On the difficult plugs I drop the plug socket in the plug hole then the 2 inch extension loosen the plug.Fish everything out with the magnet.Im sure everybody has a different methed but this works for me.Other than the smoke Id have to say its a coil-injector problem.Id start the car and start pulling plug wires and listen for a no miss.If you work on your own car this LT5 is no different.Would like to see some pictures of that G.T.O. When I was a kid my Mom had a 67 4-speed.Wish I had it now.

Kevin · 11-26-2010

Quote:

Originally Posted by GTOger

Well, I wasn't able to get with "The Guy" at the shop today due to it being a holiday weekend and all. Same story at Corey Henderson's shop down in New Braunfels. So I'm going to have to try and exercise a little patience. The tech I talked to at Corvettes of Dallas (now Corvette World as of a couple weeks ago) says he's never broken down an LT5. He's never heard of one blowing a gasket like this. (Perfect... leave it to me).

He did mention that in order to get at the heads and pull the thing apart it could be necessary to pull the engine out of the car. That doesn't sound like any bit of fun. It sounds like a whole lot of money. Anybody have any words for me? I'm starting to get a little scared. A $10k engine rebuild is not within my realm of possibilities.

about the only thing i know of that will pop a head gasket on the LT5 is dexcool. did you check the map sensor?

Z51JEFF · 11-26-2010

Quote:

Originally Posted by Dynomite

Sometimes you just have to do it

These pictures are a little misleading.If I didnt know this was a base car Id swear this was your Z with a chunk lopped out of it.

Aurora40 · 11-26-2010

I don't know if I missed it, but why do you think the headgasket is shot?

Z51JEFF · 11-26-2010

Quote:

Originally Posted by GTOger

A $10k engine rebuild is not within my realm of possibilities.

I wouldn't let my mind go too crazy just yet.When one of the injectors died in my 8000 ZR-1 I had what sounded like a rod knock I thought I was dead in the water.The knock turned out to be the flywheel-cam chains making a racket with the dead cylinder.Getting to the IH looks like a big job,it is a pain in the a$$ if you've never done it but get tons of pictures as the thing comes apart and its a piece of cake.The most valuable asset is right here,a bunch of guys that have done it.

A26B · 11-26-2010

I'm with Bob here..... I think we may be doing the chicken little thing regarding the head gasket.. Should save the worst for last. Worry when needed. BIG difference in replacing injector housing gaskets & replacing head gaskets.

EZ check for head gasket leak. Remove the radiator cap (while cool of course) watch for bubbles in the coolant.

Injector housing bolts do get loose. Loose bolts could let coolant leak into the intake runners, causing miss, white smoke & sweet smell in the exhaust, along with low coolant in the overflow reservoir. Could leak into cyl's 1,2,3 or 4. Plugs would be white. Remove plugs only when engine is cool to prevent seizing. Do a little sniff test on each cylinder while the plug is out.

Don't stress. Pretty unlikely to blow a head gasket just tooling down the road......especially on Thanksgiving with your wife in the car!

Jagdpanzer · 11-26-2010

If it is a blown head gasket or injector housing gasket coolant leak do not attampt to crank the engine over before removing all of the spark plugs or you run the risk of greater damage if a cylinder is full of coolant. With the spark plugs removed crank it over to make sure the cylinders are clear. Then install the plugs and start it up with the cooling system pressure cap removed. If the head gasket is blown bad enough to cause to the running problems you have discribed you should see air bubbeling out of the coolant pressure tank.

GTOger · 11-26-2010

Quote:

Originally Posted by Kevin

about the only thing i know of that will pop a head gasket on the LT5 is dexcool. did you check the map sensor?

I'll get out there and start looking. I'm not exactly sure *what* I'm looking for yet.

I've never seen a "good" one, but based on some pretty good pics I saw earlier

: I've got to think I could probably at least rule it out. It doesn't appear to be dexcool related.

Quote:

Originally Posted by Aurora40

I don't know if I missed it, but why do you think the headgasket is shot?

Based on advice so far and my experience with old cars (60's muscle)... steam in the exhaust & burning glycol usually says "blown gasket". Of course, I'm just not used to thinking about an IH gasket so my head doesn't automatically go there. Yet.

Quote:

Originally Posted by Z51JEFF

I wouldn't let my mind go too crazy just yet.When one of the injectors died in my 8000 ZR-1 I had what sounded like a rod knock I thought I was dead in the water.The knock turned out to be the flywheel-cam chains making a racket with the dead cylinder.Getting to the IH looks like a big job,it is a pain in the a$$ if you've never done it but get tons of pictures as the thing comes apart and its a piece of cake.The most valuable asset is right here,a bunch of guys that have done it.

That's a very diplomatic way of saying "calm down, dude."

OK. I will. All my tools are at my office so I'll either find some usable implements I've forgotten about in the garage, or I'll pick up my tools tomorrow and dig in. Thanks for the motivational words.

11-26-2010	#21
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,661	Re: 90 ZR1: Oh crud, did I break it? You might try looking up Jim Milstead known on here as "TheLurker" He's from the Dallas area and knows the ZR-1 & LT5 as well as anybody and a great guy. I'm sure he can direct you to a competent local shop.

11-26-2010	#22
GTOger Join Date: Nov 2010 Location: Dallas, TX Posts: 198	Re: 90 ZR1: Oh crud, did I break it? Well, I wasn't able to get with "The Guy" at the shop today due to it being a holiday weekend and all. Same story at Corey Henderson's shop down in New Braunfels. So I'm going to have to try and exercise a little patience. The tech I talked to at Corvettes of Dallas (now Corvette World as of a couple weeks ago) says he's never broken down an LT5. He's never heard of one blowing a gasket like this. (Perfect... leave it to me). He did mention that in order to get at the heads and pull the thing apart it could be necessary to pull the engine out of the car. That doesn't sound like any bit of fun. It sounds like a whole lot of money. Anybody have any words for me? I'm starting to get a little scared. A $10k engine rebuild is not within my realm of possibilities. __________________ [B]1990 Corvette ZR-1 (#1930) Red/Black, Stock Engine, Henderson Performance custom ECM, FIC Injectors, B&B exhaust, Kenwood DNX6160[/B] Other Rides: 1992 Pontiac Firehawk (#010), 1967 Pontiac GTO 1998 Porsche 968, 2000 Harley Davidson FXST 1986 Pontiac Trans Am, 1931 Ford Model A Tudor Deluxe

11-26-2010	#23
Z51JEFF Join Date: Dec 2007 Location: Fremont,Ca Posts: 3,079	Re: 90 ZR1: Oh crud, did I break it? Replacing the plugs are fairly easy but #8 can be a challenge.What works for me,a telescoping magnet,2 inch 3/8 extension and a 3/8 ratchet with a pivoting head.On the difficult plugs I drop the plug socket in the plug hole then the 2 inch extension loosen the plug.Fish everything out with the magnet.Im sure everybody has a different methed but this works for me.Other than the smoke Id have to say its a coil-injector problem.Id start the car and start pulling plug wires and listen for a no miss.If you work on your own car this LT5 is no different.Would like to see some pictures of that G.T.O. When I was a kid my Mom had a 67 4-speed.Wish I had it now.

11-26-2010	#26
Aurora40 Join Date: May 2005 Location: Leesburg, VA Posts: 2,713	Re: 90 ZR1: Oh crud, did I break it? I don't know if I missed it, but why do you think the headgasket is shot? __________________ Bob Saveland Former owner of #2517 [IMG]http://a.random-image.net/aurora40/vette.jpg[/img]

11-26-2010	#28
A26B Join Date: Dec 2003 Location: Arcadia,OK Posts: 3,394	Re: 90 ZR1: Oh crud, did I break it? I'm with Bob here..... I think we may be doing the chicken little thing regarding the head gasket.. Should save the worst for last. Worry when needed. BIG difference in replacing injector housing gaskets & replacing head gaskets. EZ check for head gasket leak. Remove the radiator cap (while cool of course) watch for bubbles in the coolant. Injector housing bolts do get loose. Loose bolts could let coolant leak into the intake runners, causing miss, white smoke & sweet smell in the exhaust, along with low coolant in the overflow reservoir. Could leak into cyl's 1,2,3 or 4. Plugs would be white. Remove plugs only when engine is cool to prevent seizing. Do a little sniff test on each cylinder while the plug is out. Don't stress. Pretty unlikely to blow a head gasket just tooling down the road......especially on Thanksgiving with your wife in the car! __________________ Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 *ZR-1*, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed.