I took my vette in for a drain and fill on the brake system and power steering. While they had it, I had them look at the oil leak and I was told that it was the intake. From what I read on here, a leaking intake is to be expected on a low mileage C4 (1990, 34,000 miles). But everything I read on here related to leaking Antifreeze. I just wanted to be sure you guys all agreed this probably is the problem. Also, the cost will be between $550. and $600 how does that sound to all of you? Thanks for your support!

 

What is it leaking? If it's oil, are you sure it's not your valve cover gaskets?

 

It's really an easy job takes a couple hours labor.

It is common the front and aft rails of the intake are sealed to the block using RTV. That breaks down over time and causes leaks. Nasty one's.

You'll want to pickup some RightStuff sealant, a set of intake gaskets, a throttle body gasket and while your there a set of o-rings for your injectors, and the plastic tool to release the fuel lines. In general you'll drain the coolant, pop off the throttle body, lay it aside, move your harnesses out of the way, fuel rails off, you may wish to disconnect them and while they are off replace the o-rings on the injectors, pull the intake put some rags in the valley, clean up the mess, apply new Rightstuff on the rails and reassemble. Specific steps and torque are available.

Pic ready for reassemby:

 

I am not sure that I am ready to tackle this one. I have not done any vehicle work like this for quite a while. Is there anyone in the St. Louis area that is familiar with this that might want to help? If not I will probably just pay to have this done. Is the asking price for the repair fair? The computer said it was rated at 6.1 hours. But I have heard it was a couple hours.

 

I'd say a few hours TOPS including a freese etc. however not 500.-600. worth JMO

 

Hello. Make sure that the leak is not from the oil sending/ignition kill due to low oil sending unit on the back of the intake. You will have to get the spark plug wites out of the way to check on this. The plastic innards of the sending unit will fatigue due to being in contact with hot oil and leak. The special socket used to remove and replace this unit is cheap and can be had @ 12.00 at the Autozone. You'll identify this unit as a 3"long silver sending unit with (i think) 2 wires and a big 5 sided socket head. If it is the intake gasket. It is not a hard job if you like to turn wrenches. Keep up with the bolts by drawing a picture of the motor on a cardboard piece amd poke them through where they go on the motor. The intake bolts are a bugger to get out and keep their integrity. Get a # 50 torx socket for your 3/8 drive and 1/4 with lots of extensions. The bolts under the runners are longer and hard to get to. While the plenum is off, change the EGR valve and De carbon the EGR passages and intake valves. It's not that hard to do this job. From my experience, if you have a oil or antifreeze leak learn to do the work yourself and see that it is done right. Don't trust the mechanic to love your car as much as you do. I hope you don't mind my interjection on your thread.

 

Not at all, I appreciate all of teh responses I get!
Thanks

 

Let me check with my brother he lives in St Charles he may know a few honest mechanics.

He said there is a place in St. Charles called Just Corvettes (Just Corvettes 3500 Little Hills Exwy
St Charles, MO 63301-3748 (636) 947-6060 - I did a quick search and found them. We are checking into their background will update.

 

I had the intake leak problem and I think I paid about 400.00 to 500.00 at a stealership ! Jet-Jock is probably a mech or is very mechanicaly incliend hobbiest , but I don't know about doing it yourself ...all the best , and good luck .

 

Jet-Jock metioned getting O Rings for the Injectors. I spoke to Bill in St. Louis today (he seems to be very reputable on here) and said while I am there, if I have the money, to replace the stock injectors with new GM injectors. He said they have been redesigned, and the old stock ones have a history of leaving people stranded. What do you guys think about this? My 1990 L-98 has 34,700 miles on it, shoudl I replace th Injectors while he is there? And if I should, would I still need to get O Rings for the injectors, or would the new injectors have new O Rings with them? Thanks for your time.

 

I would go with anything but GM injectors (Multec brand). THere are a number of different brands (Bosch here) that can be had for a few hundred a set. The manifold gasket kit (by Fel Pro) comes with the base, Throttle body, runners, EGR and O rings for the injectors. If you can get the motor on #1 TDC you can do this job. In fact, you can leave the Throttle body attached to the plenum if you like.
If you were more experienced Id say finding TDC isnt necessary, but the help is here if you choose to do it.

 

I am going to post a new thread on injectors. Feel free to leave more advice on the Intake Gasket. Thank you.

 

It was just a suggestion... I think the set of o-rings are something like $6.00. With that mileage you have and if you have no reason to suspect anything is wrong with your injectors don't just throw money at it. Matter of fact they don't even need to disconnect the fuel lines just depressurize the system (done in a few different ways). But the injectors can be popped out and removed as a whole fuel rail assembly and rotated up to rest on the windshield. Since your having someone do this work they will most likely do it that way it saves time.

And yes the thottle body doesn't need to be removed as it can be removed with the intake. However, things get dirty and in most cases while these parts are off TB and Intake you'll want them cleaned up like new so for a few bucks for TB gasket is worth it, as you'll be able to do a better cleaning job on the intake and TB separately. (Or whomever is doing the work.)

If someone else is doing the work for you, it's good to know what they should be doing so you know your getting a fair deal.

Plan on an oil change right afterwards to remove any foreign material for the work. Request that they clean things up while they are there if they can. Because with all those parts removed you have access to much of the engine. No sense re-assembling clean parts to dirty parts. You want the beads of RTV on the front/rear to go up just a little to meet the new intake gaskets. Some suggest putting some tap marks for better grip of the RTV but I did not do that.

Hope you gett-er fixed soon.