. This is my first post on Corvette Forum. I have always wanted a Corvette and last Xmas my dear wife surprised me with a 1991 Quasar Blue. Its has 46.000 miles and is overall in very good condition. I have just started driving it around town and getting a feel for the car. This is my first experience driving a C4, and I am LOVING IT.
Not knowing the history of the car, I am thinking of getting all the fluids changed. This is not cheap. I did examine the fluids and they seem like they are in good shape. Specially the trans fluid. Any opinions on this would be appreciated.

The noise I am hearing from the engine only occurs when the engine heats up. It is a higher pitched tapping sound that seems to be coming from the front of the motor.
I am thinking water pump. However, according the gage the car is not running hot. In fact the car is performing to my knowledge very well. Good smooth power, idles well etc. Because the sound is a tapping sound I am concerned it is coming from the valves. This Friday I have an appointment with a local garage to have the car checked over. My wife bought the car from a dealer with a 3000 mile warranty. Any tips from you experts on what I should look at or ask the mechanic to check would be appreciated.

FYI the car has had four owners, two in the last 5 years. My wife bought it from a dealership in Buffalo New York (it was a trade) and had it shipped home to Ottawa, Canada. We joined the Capital City Corvette Club and are looking forward some sunny hot cruising weather and good times.

 

Welcome to the forum. Post pics of your car when you get a chance.

 

Welcome to the forum! Sounds like you got a nice vette. As with any noise, without actually hearing it , it's just a guessing game. Maybe someone here has had this type of noise and may lead you in the right direction. Good luck!

 

Welcome to the group....I am a new member as well and there is a lot of good help here.

Just some advice....try to learn as much as you can about your car and the problem you have before you go to a garage. They will try to take advantage of you, it will be your knowlege alone will prevent you having to spend lots of money for lies.

 

Congrats on the newly acquired Vette & welcome to the forum!

With only 3000 miles on the warranty, I'd make sure she gets thoroughly checked out - preferably by a qualified shop familiar w/ Vettes.

Other than that, ENJOY!

 

Wow. What a wife. You are on lucky man. Welcome to our wonderful and often nutty world. As you are discovering there is just nothing like a C4 Vette. We are all here to help each other, so just ask and someone will pitch in with an answer, not always right, but an answer none the less. Joining the local vette club was also real good idea.

 

The LT1s were designed to run hot. Don't get freaked the first time the temp guage creeps to 227 degrees and the fans come on. Definitely get the tapping noise checked out.

It COULD be your alternator going out. I've heard them make a mechanical, clacking sound before they tank.

Enjoy your Vette and congrats. We're glad you found us here.

 

Should have said this before -- never wash the front of the motor on an LT1 engine. Water is death to the opti-spark distributor that is mounted below the water pump. Be sure w/pump isn't leaking and hoses in real good shape so they don't leak and spray on it. You mite already have known this, but sometimes new owners just can't wait to wash/clean the motor.

 

I might be wrong but I believe my car has the L98. Also to answer your other post I washed the engine compartment last night at the jet spray. I did keep my fingers crossed when I started it and drove home.
Luckily I had no problems.

 

Thanks for the reply and good advice. That's why I am trying to get a sense of what the noise may be before I take it to the garage.

 

you are correct. you have the L98.

I agree, the tapping could be anything- hard to diagnose, but you could always time the tap to determine its frequency, then you could deduce from where it might be coming based on RPM and knowledge of moving things connected to the crankshaft (i.e., pulley diameter ratios for accessories, cam driven items that are operating at half the crank rpm, etc.)

Welcome to the forum, and congratulations on your purchase! I wish you many trouble-free miles!!

 

You are right my wife is a great lady. Actually, being married to me for 27years makes her a saint.

 

Being a '91, wouldn't he have the L98? No opti, LT1 etc...

Edit: Aaaah, I see he beat me to it!

 

Welcome to the Forum!

Suggestion: since you joined the Corvette club, call up the prez, ask him who's the most mechanically experienced with the L98 in your car. Call the person if the prez will give you his/her number and ask that person to come over, or let you drive over to hear the noise/sound. All BEFORE you go to this local mechanic, who I'm sure will be experienced with Corvettes (if not, ask the club for recommendations of others).

Yes, to changing the fluids, esp. the auto trans (I'm assuming that's what you have, if not, change the man trans fluid, too). Yes, it's expensive, but think about it: this is a '91, 15 years old. Chances are VERY good that not one of the four prior owners had some or all of the fluids changed. Why? The car had what? 10K miles with the first owner, 20K with the second, etc., etc., so why would they think of changing it "at so low a mileage"?

Tell us with a follow up what happens to the car as far as outcomes and do post some pics!!! We're picture hounds!

 

I just fixed one of my own tap, tap tap problems and thought it was a (valve) lifer tap. Turned out, because it was hard to localize the noise, it was a arking from one of the spark plug wires. It was not on all the way and the front drivers side is hard to get to. It was an illusive problem.

The opti, water pump alternator is probably not going to give you tap sound. The fan belt, if I bad shape could be another possibility (small). Since only you can hear it, listening very closely and a good visual inspection is something you can do. Keep an open mind and your options open. Good luck and welcome.

 

Sorry, I was thinking you had LT1, I get my years/motors mixed up too easily.

 

If you want to see if the noise is in the engine, or on the front of the engine, disconnect the serp belt and start the car. Only let it run for 10 or 20 seconds though. If the noise is gone, it is an accessory. If not, it is internal.

 

Good advice.

 

The more you plan to work on the car, yourself, the more you need a Factory Service Manual (FSM), otherwise known as a (the) Helms. For your immediate problem, you can purchase an automotive stethoscope, or use a length of heater hose) to isolate the location of the noise. Once you are sure of where it is coming from, the easier it will be to diagnose. I agree, with the limited description, it sounds like valve train. It is one thing to adjust it out. It may be totally another to repair the cause.

RACE ON!!!

 

Thank you all for the great advice and welcoming replies. You sound like a great bunch. I am new to internet forums and still do not know how to post pics. Regardless, I can't wait until the nice weather so I can take advantage of a spring/summer backdrop. I must admit every time I look at the car I am struck with its coolness. I am the only one with a vette on my street and it draws a lot of attention. Believe me, there are a lot of high end cars in my neighborhood but the vette sure seems to turn a lot of heads. Call me shallow but I love it. I will go ahead and change the fluids on the car. As far as the noise goes, the advice to contact the Corvette Club before I bring it to the garage is a great idea. Which I will pursue. Thanks again guys. Looking forward to be part of this forum.