Welcome to the Corvette Forums at the Corvette Action Center!

Checking out a '90Z

Norsky4360

Well-known member
Joined
Apr 28, 2002
Messages
64
Location
Minne-snow-ta
Corvette
'70 convert ("The Toy"), '90 ZR-1 ("The Beast")
Checking out a '90Z - IT'S IN THE GARAGE NOW...!!!

My wife and I are in the final stages of purchasing a 1990 ZR-1. It has 7,550 miles on the odometer. Later in the week (possibly Thursday weather permitting) a pre-sale inspection is scheduled at a local "Bow Tie" dealer (lots of Vettes around there all the time - both on the lot and in the service parking area).

My wife and I test drove it last Saturday and other than the cruise control not wanting to engage and the "Low Tire Pressure" warning lit up (tire pressures were ok) there were not any glaring issues. I've checked the ZR1 Net Registry site for info and that has been very helpful (THANKS SCOTT!!!) but I have a couple of lingering questions (other than trying to figure out how to pay for the beast!).

- I asked what is on the checklist for the inspection and it seemed rather brief. Anything out of the ordinary I should ask to have checked?

- This is a very low mile car (average of 470 miles/YEAR). Any concerns or things to do before getting this car back where it belongs - on the road?

There isn't much of the driving season left up here in Minnesota so it will be parked soon for the snow season. That being said, we'd like to enjoy driving it some before the MDOT trucks start spewing the winter crud on the roads.

Thanks!
 

Rob

Site Administrator
Staff member
Administrator
Joined
Sep 16, 2000
Messages
13,589
Location
New Hampshire
Corvette
1990 Corvette ZR-1
Hi Jim,

Sorry for the delay in replying. I've been kind of swamped around here.

Check the oil cooler lines. The oil cooler lines run from the front/passenger side of the engine block, near the oil filter housing, and into the passenger side of the oil cooler, near the top, under the radiator shroud. They tend to leak on the earlier models right where they screw into the oil cooler. If they are, pickup a set at your local Chevrolet dealer (they'll probably have to order them). GM redesigned them slightly in later models.

Chances are one or more of the LTPWS sensors are bad. There is a way to check these which I believe is in the service manual. There's also a Service Bulletin on this which might provide additional information:

http://www.corvetteactioncenter.com/kb/question.php?qstId=167

One of the other things to check is the secondary port vacuum pump. Rather than to go into detail here about how to check that, please see this thread at the top of this forum:

http://www.corvetteactioncenter.com/forums/showthread.php?t=14272

As for getting it back on the road properly....make sure all fluids are changed - coolant, oil, tranny, rear-diff, brake fluid, etc. Go over all the weather stripping, and other rubber components in and around the engine with Meguiars #42 - Rubber and Vinyl Cleaner and Conditioner. Check the tires (if they are the original Gatorbacks) for dryrot or cracking. If you see that, get new tires. In fact, if it is running the Gatorbacks and they look fine, replace them anyway. Those tires are horrible and utilize, OLD tire technology.

Once you get all the fluids changed, etc., go out and take it on a maiden voyage. Ease into it. Don't immediately go out and pound on it. Play with it a little. Work the secondaries. The secondaries will kick in at approximately 2,300 - 2,800 rpm depending upon throttle input. With each drive in succession, push the car a little harder.

The LT5 engine LOVES to breathe and loves the upper RPMS (not to mention cool, crisp, Fall air!).

DRIVE the ZR-1 like it was meant to be driven. Get the fluids flowing hard, and I guarantee, the LT5 will reward you by putting a smile on your face that won't soon leave you.

When you first start driving the car, she may buck, she might run a little rough, etc. She might even feel a little underpowered. The more you drive it, the more things should smooth out and the engine should feel normal again.

Good luck and keep us posted!!!!!!
 

Norsky4360

Well-known member
Joined
Apr 28, 2002
Messages
64
Location
Minne-snow-ta
Corvette
'70 convert ("The Toy"), '90 ZR-1 ("The Beast")
Rob - thanks for the reply! I've already read the thread on the secondaries pump and will read the service bulletin one.

The experience continues.

On the way to the Chevy dealership Thursday night for the inspection I pulled into a parking lot to check a few things myself. Found that the radio/cassette/CD and/or speakers are not up to full operating condition. Lots of "buzz and crackle" and little else from the radio (tried several stations), the cassette would load and spin but no sound, and the CD would not engage and grab an offered platter. Good news - the antenna went up when the radio was switched on. Bad news - it stayed up when the radio was switched off. I've read that the Bose equipment was full of problems and replacing it may be the better option in the long haul. But for now it is a bargining point.

At the Chevy dealership the tech reported the car ran out fine (the gearbox seemed smooth, solid, and shifted easily, the three suspension settings were distinct, the power switch worked, the car tracked straight and the brakes were solid) except for the cruise control not wanting to engage.

I asked if there was any way to check out whether the injectors are the original ones without pulling anything apart (first rookie question). The tech said no, the only way was to pull the plenum and take a peek. I know the selling dealership isn't going to authorize that before the sale.

While up on the lift it was noted that there is a small coolant leak on the lower radiator hose and evidence of a small oil leak towards the rear of the oil pan. Otherwise it was very clean.

As expected all four tires have cracks developing in the tread groves (but none on the sidewalls). They appear to be the original skins so will see what the salesman has to say about that. I'm going to guess that replacing them will come out of my pocket.

The tech also noted that the heater/AC controls were not functioning. He felt that he was not qualified well enough to diaognose that or the cruise control so it would be best to bring the car back in again on Monday when their lead Corvette tech would be back from vacation. I really appreciated the tech telling me he was in a bit over his head and recommending that the inspection be continued by a more qualified tech. I've never had that happen before!

I had the heater/AC control head die in a '93 Chevy pickup I owned years ago and it was a simple thing to replace (don't remember the cost of it tho'), but again another bargining point. The non-functioning cruise control the selling dealership said they'd fix, unless there were lots of dollars involved.

So the appointment was scheduled for Monday to continue the inspection and we'll see what happens then. I don't think the salesman was very happy when I returned the car with the list of things wrong with it longer than when I left AND that it needed to go back to the Chevy dealer for more investigation. IMO they should have known all of this already had they done any kind of a checkout of the car when they took it in.

And to this point the prior owner has not answered any requests for information on the car (like the where-abouts of the owners packet, service records, etc) that I've asked the sales folks to get. They have not (and probably will not) share his name with me. They don't want to bug him too much because he is (supposedly) a high profile company executive in the TC metro area and don't want him to get PO'd enough to take his new car business some place else.

Thanks again for the info!
<!-- / message -->
 

Rob

Site Administrator
Staff member
Administrator
Joined
Sep 16, 2000
Messages
13,589
Location
New Hampshire
Corvette
1990 Corvette ZR-1
Hmmmm, ok.....

Radio crackle, etc. A crackle I've never experienced. I bought my '90 back in Sept. of '94 with 179 miles on it. I currently have around 31,000 on it. Just recently, one of the speaker amps met God. I rarely ever use the radio in the car because I enjoy the sound of the engine and exhaust. However, you can ship all 4 speaker assemblies back to Bose in Framingham, MA, and they'll fix any problems and update the internals to new, improved components.

I just spoke with them this past week and will be removing all 4 assemblies from my car while it's in storage for the winter.

As for the tires, replace them. Save the originals in case you ever decide to sell the car, but definitely replace them with better tires.

There is no way to check the fuel injectors without taking the plenum off. Considering the low mileage of the car, I'd doubt they have been replaced. It's not something I would worry about at this point in time, but eventually, you may want to replace them with better injectors.

I highly recommend stainless steel injectors from RC Engineering in California. I replaced mine. Big difference. I can't rememeber RC's contact information, but they are listed here in the Portal section of the CAC.

The oil and coolant leak is not surprising, considering the low mileage of the car and how long it's been sitting. Gaskets and hose seals tend to go bad when they don't see a regular work cycle.

As for the heater and AC controls not working, this is something I've never experienced. I've never had any problems with my HVAC system. Same with the cruise control, although I never use it. Last time I used it was probably when I took the car down to Bowling Green in April of '95 to see the last ZR-1 come off the line.

Have the dealership simply call the previous owner and explain to him that they have a prospective buyer who would like to talk to him and ask him if it would be ok to give out his number to you. That's what Bud's Chevrolet in St. Mary's, OH, did for me. I spoke to the previous owner for nearly 1.5 hours. He owns a huge tool company up in Canada, and I have a complete history on the car, from the point he ordered it to the point he sold it.

Keep me posted on what the inspection on Monday yields!!

-Rob
 

Norsky4360

Well-known member
Joined
Apr 28, 2002
Messages
64
Location
Minne-snow-ta
Corvette
'70 convert ("The Toy"), '90 ZR-1 ("The Beast")
Well - it's a done deal.

The car came through the pre-sale inspection better than first thought. The cruise control issue turned out to be a vacuum hose that had fallen off. The HVAC controls issue was a blown fuse, as was the radio (though it still has issues - probably corroded connections or terminals from lack of use!). The radiator hoses should be replaced (will do that when changing all of the fluids) and the tires will need to be replaced before venturing too far from home.

But tonight "The Beast" is in the garage next to "The Toy", both tucked under their covers. Still hasn't sunk in that we bought it. I'll believe it more when I walk out into the garage in the morning and it's still there.

Thanks for the info and advice. It truely is much appreciated.
Patty & Jim
 

Rob

Site Administrator
Staff member
Administrator
Joined
Sep 16, 2000
Messages
13,589
Location
New Hampshire
Corvette
1990 Corvette ZR-1
That is awesome!!!!! I'm glad everything worked out for you and beast is home now.

Please keep us posted on the car and how things go.

Congrats!!!
 

Wegone

Well-known member
Joined
Apr 9, 2002
Messages
516
Location
Atlanta GA.
Corvette
82,91 ZR-1,
Congrats on your new ZR-1...
 
Joined
Sep 16, 2003
Messages
522
Location
Newark, OH
Corvette
2003 50th Anniversary Convertible
Congrats on the BEAST!! You will love it!! Check on the ZR1netregistry site for the group purchase of the coolant hoses from Samco. I got mine last year because mine had a leak as well.

The Z is definitely a wolf in sheep's clothing.

Jim :beer
 

Wegone

Well-known member
Joined
Apr 9, 2002
Messages
516
Location
Atlanta GA.
Corvette
82,91 ZR-1,
Nice pics....
 

Norsky4360

Well-known member
Joined
Apr 28, 2002
Messages
64
Location
Minne-snow-ta
Corvette
'70 convert ("The Toy"), '90 ZR-1 ("The Beast")
#682

According to the salesman it lived most of its life in a climate controled space in Arizona. I don't know (yet) where the original owner took delivery but it was transported back to Minnesota early last summer. The BMW/Mercedes dealership we purchased it from took in trade last June. They had it on their showroom floor for awhile priced at just under $36K. We snatched it for considerably less as they're trying to clear their inventory of summer sporty cars.
 
Joined
Sep 16, 2003
Messages
522
Location
Newark, OH
Corvette
2003 50th Anniversary Convertible
Great pics!! That is a beautiful car!! Congrats again!! Beware of the perma-grin that is associated with these cars!!

Jim
 
Joined
Dec 19, 2003
Messages
328
Location
Grand Rapids,Mi
Corvette
89 White Cvt/Hdtp 89 Callaway #59
:_rock Congrats on the new toy! Hope to add one to my collection eventually! The scream of the LT-5 appears to be addictive. Still remember when they were new and I heard one on a portable dyno! :upthumbs
 

bill81vette

Moderator
Joined
Jan 17, 2004
Messages
4,268
Location
Troy,NY
Corvette
1981 dark blue metallic
Congrats on the ZR-1...hope you get to enjoy it b/4 winter sets in over there!!! :D

hopefully in a few years,I'll have one next to the '81....
 

bowtieollie

New member
Joined
Jul 1, 2003
Messages
1
Location
somewhere in Pennsylvania
Corvette
1986 Pace Car yellow; 1990 ZR 1
oil cooler lines

Hi Rob,

Check the oil cooler lines. They tend to leak on the earlier models right where they screw into the oil cooler. If they are, pickup a set at your local Chevrolet dealer (they'll probably have to order them). GM redesigned them slightly in later models.


Has anyone ever determined what exactly changed on the oil cooler lines?
90-93 was one part number.... 12472184
94-95 was different.

It is my understanding that the 94-95 lines will not fit a 90-93.... and guess what? The 90-93 are long discontinued by GM and no dealer has one in stock, nor does Vintage parts.

The hoses can leak at either end where the steel collar is crimped to the fitting.
 

Rob

Site Administrator
Staff member
Administrator
Joined
Sep 16, 2000
Messages
13,589
Location
New Hampshire
Corvette
1990 Corvette ZR-1
Hi Rob,

Check the oil cooler lines. They tend to leak on the earlier models right where they screw into the oil cooler. If they are, pickup a set at your local Chevrolet dealer (they'll probably have to order them). GM redesigned them slightly in later models.


Has anyone ever determined what exactly changed on the oil cooler lines?
90-93 was one part number.... 12472184
94-95 was different.

It is my understanding that the 94-95 lines will not fit a 90-93.... and guess what? The 90-93 are long discontinued by GM and no dealer has one in stock, nor does Vintage parts.

The hoses can leak at either end where the steel collar is crimped to the fitting.

I'm not sure. I replaced mine with a newer set a while back because mine started leaking. I still have the original set. I'll have to take a look at them and it may job my memory.
 

Norsky4360

Well-known member
Joined
Apr 28, 2002
Messages
64
Location
Minne-snow-ta
Corvette
'70 convert ("The Toy"), '90 ZR-1 ("The Beast")
Whoops - I think some thread lines got tangled up?!?!?
 

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Win Both Corvettes!

Win Both Corvettes and Get Extra Bonus Tickets Now!

Supporting Vendors

Dealers:

MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Parts/Accessories:

Dead Center Foundation

Vetteskins

Advertise with the Corvette Action Center!

Partners

Top Bottom