LT-5 motor issue

[JimBobTX]

I took my 1990 ZR-1 out for a short ride about a week ago, after not having out for a month or so. I drove about 40 miles total to get get gas. The only gas I run in it is ethanol free 93 octane. On the entire trip the car seemed to be a bit sluggish but more so on the way home. My initial thoughts were that perhaps I had some condensation, or water, in the gas lines, so I then planned to check my fuel line filter for possible water.

When I cranked the car up a few days later the exhaust output was extremely white, which is the first time this had occurred. I then backed the car out of the garage to not fill the garage with smoke, but upon exiting the car it was obvious that the white exhaust was not oil but water. The white exhaust did clear about the time I got the car out of the garage. I could hear a distinctive tapping ( clicking sound) from under the car, which I had never heard before. I listened to the exhaust and also under the hood but could not hear the noise from ether the exhaust or under the hood. I pulled the car back in the garage and shut it down.

I assume that I have an internal engine problem. I have owned the car for almost 3 years and have put about 600 miles on it and it now has about 25,600 miles.

If anyone in the Houston Texas area has any recommendations of a shop where the mechanic might be familiar with these engines I would appreciate it. I do not plan to drive to a shop but will have it taken to the shop on a carrier tow truck.
Thanks
Jim Miller
(MillerJimL@yahoo.com)
(281-743-4021)

[Z51JEFF]

Corey Henderson is in Texas,very knowledgeable with ZR-1s.

[sleazy rider]

Corey Henderson is in Texas,very knowledgeable with ZR-1s.

cory is in new braunsful. steve schroder, crossed flags performance, is in magnolia. 832.748.1286

[JimBobTX]

Great suggestions, New Braunfels is about 160 miles and Magnolia is about 22 miles from my house, so I will give Steve a call tomorrow morning. Thanks for the suggestions, I really appreciate it.

[Mikey]

Sounds like coolant in the combustion chamber. Do you notice any milky appearance or light brown on the oil dipstick?

[JimBobTX]

That is exactly what I thought too, which is why I thought I had water in the fuel but the tapping noise under the car bothers me. I am glad not to hear anything directly at the engine under the hood or out the exhaust but the oil on the dipstick looks good, nothing milky, only oil. Oil still looks good, even though I could use a change, but it was only 400 miles ago I had it changed.

[Z51JEFF]

Does the motor sound like it's got a miss? The cam chains and DM flywheel will make a racket if not wiring on all 8.

[JimBobTX]

Actually the motor runs fine at an idle and was running good at low speeds and I could not hear any engine noise. It seemed to run just fine until I tried to accelerate that it seemed sluggish when I took it for a drive last week. I didn't try to drive once I saw the white exhaust discharge but there is not noticeable unusual engine noise from the engine bay.

[LGAFF]

Injector housing bolts loose or gasket failure can pull coolant into the intake tract.

[LGAFF]

http://zr1.net/forum/showthread.php?t=20076&highlight=gasket+failure

[Ccmano]

Lastest word on Cory Henderson is that they will build LT5 project cars but will not do maintenance or repair work on anything other than the cars they build. (Hope I'm wrong about that) Crossed Flags in Magnolia is probably your best bet.
If you don't have the skills to work on the car yourself, Steve at Crossed Flags can get you fixed up. It might be worthwhile giving him a call.
H
:cheers:

[Paul Workman]

Injector housing bolts loose or gasket failure can pull coolant into the intake tract.

DITTOS on the IH bolts, AND the plenum bolts too!

Blue "Loctite" will be your friend on ALL the bolts under the plenum & the plenum itself, along with gaskets from Jerry's Gaskets (https://www.jerrysgaskets.com/) (was the cure to my leaking issue when I first started driving my Z. Never a problem since in 40k miles!

[JimBobTX]

I will certainly give Steve a call this morning to see if he can have a look at the car. If he can I will have it towed there. I don't wish to cause any further problems with the car. I have, or did have, the skills to work on most auto issues on pre '72 cars, at least those without emissions and computer parts, but at my age I guess I will just have to rely on others to help with the more modern cars. At 73 there is still a lot of general repair/maintenance work I can do but I will leave the heavier work to someone who really knows what he is doing. I really appreciate the comments and suggestions from all of you. Thanks.

[DRM500RUBYZR-1]

Certainly agree on taking it to Steve!!!

Although, did you check to see if your coolant level was low, or lower since the last time you checked?

Was your last fill up for fuel from the same (trusted?) place you have been using?
Did it begin soon after last fill up?

Was the car outside in the rain or was it washed?
If either, check to see that the fuel boot drain is clear.

The Flywheel will make noise with even minimal performance degradation.

It would be very helpful to know if the coolant level has or has not dropped.

Often, it is the simple things rather than mechanical failure, particularly on an LT-5 engine.
While you cannot rule out coolant, I have had a number of supposed coolant leak complaints that were either excessive condensation burn off, or water contaminated fuel.

Always good to start checking the simple and obvious first, before proceeding to the less common ones, although the aforementioned IH or bolt / gasket leaks are good culprits if it is ingesting coolant.

Keep us posted.
:cheers:
Marty

[wfot]

were the injectors changed? I am aware the white smoke is not direct relation to the injectors, but if someone is going to pull the plenum......

John

I say this because the 90 - 92 injectors are known to fail due to the internal orings breaking down and the injector failing. no offense, not sure how aware you are of this issue...

[JimBobTX]

coolant level is on low side but there is still some in the reservoir and I have gotten the fuel from the same place each time and only run ethanol free in it. I have never put a hose to the car, I always wash by hand with a hand duster and sprayer and soft cloths and it has never been parked outside since I have owned it.

Tje Plenum was removed two years ago to have new injectors installed. This was done at Corvette World here in Houston. I had a power problem when I bought the car and the work that they did at Corvette World did not fix the problem but what is happening now is different and yet may be a result of. poor work done at that time since I have not really driven the car very much since then.

I have put a call into Steve Schroder and left him a message, hopefully I will hear back from him today to discuss the problem.

Thanks again ro all for your suggestions, comments and recommendations.

[JimBobTX]

Thanks again to all. Steve Schroder has agreed to have a look at it. I really appreciate the contact.

[jss06c6]

Jim,

Thanks for reaching out. I'd be very happy to help you! The LT-4 we spoke about won't be here until the 8th or 9th. I'll drop you a text so we can get your ZR-1 up here and get her breathing on all 8 cylinders and all 16 injectors!

Steve Schroder

Sent from my SM-G950U using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[ZR2]

Sounds like a coolant leak in the plenum. It would not cause the oil to get milky as if it were a warped or blown head gasket. I know my 1st time taking the plenum off a previous ZR1 I owned to replace injectors I did it 3 times before perfection!! Once was a coolant leak issue with much white smoke and another was a vacuum leak with no coolant leak but an idle of 1800 rpms and then the 3rd time......the charm. I would be surprised if the injectors had not been replaced on your car, but your lack of power description is what mine felt like when th injectors were not working and went bad in my 91 ZR1 I had.

[ZR2]

Didn't see the post that said the injectors were replaced 2 years ago?????

[rkreigh]

do a coolant system pressure check and I'm afraid you might find bad hg or certainly something dumping coolant into the engine which is no bueno.


I need to call Corey, I'd be a little surprised if he wouldn't work on the car.


Keep us posted!!

[Paul Workman]

Injector housing bolts loose or gasket failure can pull coolant into the intake tract.

Myself and some others ran into a spate of that related to gasket failure. But, the gaskets from Jerry's Gaskets ended that fiasco! Never a problem since.

And, as a precaution, I use a little 3M gasket sealer around the coolant port between the head and the injector housing.

Finally, the bolts clamping the gaskets on both the intake manifold AND the injector housing, had a tendency to work loose. I learned this from someone on this site, and when I checked the torque on the IH bolts, sure enough they needed re-torquing. So, I put some BLUE Loctite on all of the threads before torquing down the IH or the intake plenum. The top of the motor hasn't been off in probably 8 years now - and no white smoke!

[jss06c6]

Jim's beautiful 1990 is back to full strength.. there were a number of issues, none of which were serious, but caused very poor performance. Quick list below..

1. Dead Coil
2. Fouled #4 plug
3. Badly leaking #4 primary injector
4. Leaking Injector Housing Gaskets
5. Leaking Secondary Vacuum Solenoid
6. Failed Secondary Injector Relay Module

All repaired and now strong again!144361443714439144401444114442

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[JimBobTX]

As a follow up to my original post, I wanted to report the final solution. I had the car hauled to Cross Flags Performance (Steve Schroder) and am extremely satisfied with the results. I would highly recommend Steve as a go to guy for performance issues, and probably any issue, as it relates to C-4's or especially our ZR-1's.

If interested I have posted below a brief history of my performance issue.

I purchased my ZR-1 at the Barrett-Jackson, Palm Beach, auction in the spring of 2018 and once I had it shipped home I discovered that in power mode the engine cut out and seemed to run on only some of the cylinders. Being dissatisfied with the performance I contacted the service manager at Corvette World in Houston. He told m that he was experienced with the LT-5 engine and could correct the problem. They had the car for 3 months and I was told that they tired a lot of different things, including new injectors and when I got the car back it didn't ruin any better than when I took it in. So for the past two years I just drove it occasionally with no expectation of being able to drive it in the Power Mode.

Earlier this month I took it to get gas and noticed a significant problem in performance and the engine seem to cut out or misfire in normal mode. After a few days I started the car again and this is when I noticed the white exhaust that had a faint odor of anti-freeze and posted my question about who to take the car to on this forum.

I took the car to Steve and he was able to fix all of my performance issues in the car. Unfortunately many parts for these cars are no longer manufactured, or even available anywhere, but Steve was able or either disassemble, and clean/repair, or locate used parts for what were needed to repair my car, and for that I am very pleased. If any one is interested interested in exactly what Steve had to do to correct my problems, I will leave it to Steve to explain the details.

All I can say for certain is that my problems were solved and I am extremely satisfied with the way the car performs, my interaction, and communications, with Steve during the repair and the ultimate cost of the work. I would highly recommend Steve for anyone needing help with the ZR-1.

[JimBobTX]

By the way, I want to thank everyone who posted their suggestions here. I would have not been aware of some of the problems that were suggested and I would not have found Steve if not for the posts here on this forum. Thanks again.

[jss06c6]

As a follow up to my original post, I wanted to report the final solution. I had the car hauled to Cross Flags Performance (Steve Schroder) and am extremely satisfied with the results. I would highly recommend Steve as a go to guy for performance issues, and probably any issue, as it relates to C-4's or especially our ZR-1's.

If interested I have posted below a brief history of my performance issue.

I purchased my ZR-1 at the Barrett-Jackson, Palm Beach, auction in the spring of 2018 and once I had it shipped home I discovered that in power mode the engine cut out and seemed to run on only some of the cylinders. Being dissatisfied with the performance I contacted the service manager at Corvette World in Houston. He told m that he was experienced with the LT-5 engine and could correct the problem. They had the car for 3 months and I was told that they tired a lot of different things, including new injectors and when I got the car back it didn't ruin any better than when I took it in. So for the past two years I just drove it occasionally with no expectation of being able to drive it in the Power Mode.

Earlier this month I took it to get gas and noticed a significant problem in performance and the engine seem to cut out or misfire in normal mode. After a few days I started the car again and this is when I noticed the white exhaust that had a faint odor of anti-freeze and posted my question about who to take the car to on this forum.

I took the car to Steve and he was able to fix all of my performance issues in the car. Unfortunately many parts for these cars are no longer manufactured, or even available anywhere, but Steve was able or either disassemble, and clean/repair, or locate used parts for what were needed to repair my car, and for that I am very pleased. If any one is interested interested in exactly what Steve had to do to correct my problems, I will leave it to Steve to explain the details.

All I can say for certain is that my problems were solved and I am extremely satisfied with the way the car performs, my interaction, and communications, with Steve during the repair and the ultimate cost of the work. I would highly recommend Steve for anyone needing help with the ZR-1.Jim, that's very kind of you. It was a priviledge to help you with your ZR-1! I'm always here for you for anything you may need..

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