ZR-1 Maintenance Tips

General Maintenance

by Jim VanDorn


The most common call we receive by far is from a confused ZR1 owner. After years of reading everything from which thermostat to use, to what type of spark plug is best, the average owner is totally and completely confused...and for good reason. There are many varied opinions of what is best for our cars but that may depend greatly on how you use your ZR1.


After seven years plus, many ZR1's are finally accruing some mileage. We have had the opportunity to closely inspect many engines with a variety of types of use from normal street driving to severe "weekend" use (track time). Compiling this information we can now offer the ZR1 owner some observations. One rule we've adopted after hearing so many owners say the same thing is the "DIMWIT" or "Darn, if I didn't Mess With IT" rule. In other words, if you didn't have a problem, then what are your intentions in the first place? To date, the only company known to have a fleet of engineering ZR1's to test with was GM and it's affiliates.


Therefore, we must ask ourselves if their suggested procedures and parts recommendations should have a considerable amount of merit. Obviously they do, but on the other hand, there are no doubt areas for improvement. Although we will begin our segment discussing the routine and normal maintenance of the ZR1, there are many areas where an upgrade will be suggested.


Please understand that these are personal opinions and experiences and are not intended to conflict with service procedures outlined in the appropriate service manual.

This is most common on late 1990, or early 1991 Corvettes and ZR1's.

Rear hatch glass is touching or almost touching the fiberglass lip near the gas tank flap on one side, but has about 1/4 inch gap on the other side. Additionally, if the glass has shifted down too far, the hatch latch striker may show signs of abrasion, and the plastic trim may be dented or broken.


Procedures and Cure:
If you have a really different (intermittent screeching / creaking / scraping) sound that the dealer cannot identify, combined with a mis-aligned rear hatch glass, it might just be a glue adhesive failure. You may find that the sound travels - seems like it is coming from different areas at different times. You may take the cabin back interior trim off and notice nothing loose.


Back in the days of the CAC, good old Jerry Watts knew what it was immediately. Jerry faxed a copy of the service alert #93-131-10 about the adhesive failing on the rear hatch. At first, I could not believe it since the checking procedure included opening the hatch fully and trying to notice a wiggling or looseness when pushing up further - which my glass did not seem to do (I wasn't pushing up hard enough). But Jerry was right about many other things, so back to the dealer we went. With the procedure bulletin in hand, the dealer took my car to the auto glass shop nearby where they removed the glass hatch, re-glued it, and bolted it back on - problem solved: $100 bucks, plus whatever the dealer charged for "diagnostic charge". Yes, the glue supplier had provided defective glue for a time period, and it was changed when the GM factory found out about the failures. I am not aware that one can do this repair at home since the glass handling is tricky and the hatch is very heavy and expensive. So, just take the car to a reputable glass business and instruct them to remove and re-glue the hatch glass.


The removal procedure, not the re-gluing, is described in the GM Repair Service Manuals ST-364, section 10-8.


by Randy Schulkers

Posted in: Body, Glass
Post Comment
Only registered users may post comments.

The information contained in this website is for general information purposes only. Whilst we endeavor to keep the information up-to-date and correct, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the website or the information, products, services, or related graphics contained on the website for any purpose. Any reliance you place on such information is therefore strictly at your own risk.

In no event will we be liable for any loss or damage including without limitation, indirect or consequential loss or damage, or any loss or damage whatsoever arising from loss of data or profits arising out of or in connection with the use of this website.

Through this website there are links to other websites which are not under the control of the ZR-1 Net Registry. We have no control over the nature, content and availability of those sites. The inclusion of any links does not necessarily imply a recommendation or endorse the views expressed within them.

Read the full Disclaimer...

©2019 ZR-1 NET Registry   |  Privacy Statement