Newbie needs help with 1988 corvette.

[fast88]

I just traded up my camaro for a 1988 corvette. I got it with some problems and been unable to fix them alone. Anyone out there have answers to these following questions.
1. Where does the EGR vacuum lines connect specifically? All are connected except one which I believe goes to the throttle body. But where at on the throttle body?
2. I have an oil leak on the right side of the engine. I understand that it could be the valve cover gaskets, but I changed both of them already. I am running SAE 40 because it is an older engine could that cause the leak? Otherwise, what sensor or mechanism would the leak come from on that side?
3.The hood lights, seat rails, horn, back-up lights and electric locks do not work. Is there a common electrical component/relay/fuse that would cause this problem? If not what could it be?
Thanks I appreciate the help and input.

 

[XLR8]

I can't help with your technical questions, fast88, but I wanted to say welcome to the Corvette Action Center and congrats on your upgrade!! There should be some traffic along soon with more advice/info than I can offer. This is a great site with friendly and knowledgeable Corvette enthusiasts!

Good luck with your issues. Hope you get them resolved quickly.
Jane Ann

 

[XLR8]

BTW... here are a few links which may interest you too:

CAC | Tech Center

CAC | Model Center

CAC | Model Center | 1988 Model Center

Enjoy!

 

[fast88]

Jane Anne,
Thanks for the reply and it is a pleasure to be a new part of this forum. I would like to say that I do not have a lot of issues with my 88, but being that is 20 years old I am not surprised of the ones I do have. It really is an amazing sports car model. One which always wanted to own. I bought a shop manual and it helps, but some of these pressing issues are ones I need more expertise in. Thanks again and nice car!
Steven

 

[XLR8]

Thank you for the kind words about my ride, Steven. I've always liked the grey C4s also. Any chance you can post photos of it?

Here's a link to the Site Help and Feedback Forum which contains several threads regarding photo posting in case you need them.

And again, congrats on your first Corvette and welcome to the CAC!
Jane Ann

 

[JAKE]

WELCOME ABOARD!

It's be a while since I worked on a L98 engine, but from memory, there's a hose bib on the front, underside of the throttle body that vacuum hose connects to. I can't recall if it's for the EGR though, but check there to see if anything's connected.

When you posted "right side" of the engine, are you referring to driver or passenger side? There are a number of places where an oil leak can occur.

Is the leak near the front or rear of the engine?

Best way to track down a leaking location is to clean off all the oil from the area, then fire the engine and let it idle and occasionally wing the throttle a bit. Winging will cause the oil for splash around more in the areas where the leak actually is. See if you can locate where the oil is leaking from. I use the cheapest carb cleaner in can find to spray off all the accumulated oil.

There are additives that can be added to the oil that will show up where the leak is. But before going that route, I'd first try the no-cost approach.

I don't recommend straight 40W oil, it's too heavy to flow well when cold. This could cause accelerated bearing wear. Valvoline 20W50 Racing oil would be my choice. Less resistance when starting a cold engine but will maintain higher oil pressure once the oil reaches normal operating temperature.

Keep us posted on what you come up with.

Jake

 

[JAKE]

I forgot; whenever you have an electrical component that doesn't work, the first thing to check is the fuse. Yours are on the passenger side of the dash, accessed when the passenger side door is open.

Each fuse location is marked, but you might as well pull and replace each fuse, one at a time just to cover all the bases.

If all the fuses are good, then next thing to check is the relay. I'd have to track down my Factory Service Manual for my old 86 to see where the relay(s) are mounted. I suspect your 88 and my old 86 are the same.

Hope this helps.

Jake

 

[TnTom]

Fast88,
Gotta get the Factory Service Manual and the Supplemental Electrical Service Manual, and Chiltons. There are some things (cooling fan for sure) that are covered well in the FSM and Supplemental and are elaborated on in Chiltons. All 3 manual helped me get through the window issues, cooling fan issues, head lamp issues, power antenna issues. I really had to sit down and study the schematics but they are well done and eventually make sense. Chiltons steps you through some testing methods that the factory manuals just say to do. Chiltons can tell how to do them. The factory manual shows you where the relays are located with some good photos.
There are also good vaccum line illustrations. I have an '84 that had most of the problems you have talked about.
Need to get a good multimeter and get familiar with it.
Tom

 

[fast88]

Jake,
Thanks for the welcome. As for the EGR relay vacuum hose. It is still sticking out of the relay assembly which would be mounted against the upper connection of one of the radiator hoses. You mentioned the "hose bib", I think I would do better with an underview picture of the throttle body with an exact location...if you can. As for the oil leak. It is on the passenger side near the rear bottom portion of the engine. It usually spashed up pretty good if I tach it up on the road...otherwise at idle nothing. As for the electric... I checked and replaced all of the fuses on the passenger side fuse panel near the door. Is there another set of fuses I don't know about?
Thanks,
Steven

 

[fast88]

Jane Anne,
When I get some of the bigger problems solved, I will get a fresh wash and a new wax coat and then I will take some pictures and send them out. To me it is still "work in progress" therefore it will have to wait.
Thanks for the words of encouragement.
Steven

 

[JAKE]

In my 86 FSM, it states that there is an Auxiliary Fuse Block behind the center of the multi-use center (dash) that has a fuse for the horn.

There's also a Fusible link at the left hand rear in the engine compartment below the cruise control servo.

I suspect that your 88 is the same as my old 86, so I'd first check the Fusible Link (since it's the easiest to access), then the fuse behind the dash. From memory, when I removed my dash I saw that fuse and at least one more.

The fuse you'll be looking for behind the dash is the THEFT FUSE.

I'll check my FSM for the door locks, seats, B/U lights etc to see if there's anything in common and I'll post what I find.

Jake

 

[JAKE]

My FSM says there's a 30 AMP Power Accessory (PWR ACCY) circuit breaker IN THE fUSE BLOCK (right hand end of the instrument panel). This is for the door locks.

The only two things I've in common so far is the THEFT DETERRENT CONTROLLER, which is identified as being located "Behind RH side of I/P".

The FSM states, in part: "NOTE: If both doors will not operate, check that the PWR ACCY Circuit Breaker and the door lock motor connectors are clean and tight."

Hope this helps.

Jake

 

[fast88]

Jake,
Thanks for the help on the electrical question. I will check into that. Any idea what could be causing the oil leak. That is my main focus. As I said before it is on the passenger side near the back of the engine. There is a sensor plug, I believe a coolant temperature sensor. Could that leak oil? Or is that strictly a anti-freeze type of plug? Is there something below in that area that get shoot oil upwards to cause that effect when road tested? I changed the oil back to 5/30 and am trying an oil dye as a last resort before taking it to a shop.
Thanks,
Steven

 

[JAKE]

I don't know of a way to check the relays, but since they're so inexpensive buying new ones shouldn't be a problem.

No, the coolant temp sender that's mounted in the passenger side head would only leak coolant. Below that, in the block, is the knock sensor but it, too, would only leak coolant.

Take your hand or a paper towel and run it under the lip of the valve cover and see if it comes out wet with oil. Also, do the same thing with the extreme rear of the intake manifold where it meets with the cylinder heads. That's what we call the China Wall; there's two of them one at the front and one at the rear. They are common areas of oil leakage, due to age and drying out of the gaskets.

At the base of the distributor is another spot that can leak oil. There should be a gasket between the intake manifold and the distributor base and it can occasionally leak.

Sometimes new valve cover gaskets can take a set after the engine has run a while When this happens the clamping pressure is lost and oil will leak at the gasket where the valve cover meets the cylinder head. Cork valve cover gaskets are notorious for this. Best ones are the rubberized gaskets that have torque limiters (little washer like arrangements that help prevent over-torqueing) at each bolt hole.

Check that the torque is holding on the four valve cover hold down bolts but be sure not to over-torque them because they could break. Ask me how I know.

Keep me posted.

Jake

 

[vetteoz]

Also the oil pressure sensor and oil presure switch are mounted at rear of block behind dist.
Common for them to leak under pressure with age.
Oil then runs down back of block and drips on starter.

 

[muddywaters]

On my 88, the circuit breaker for the door locks also powers the seats. The seat adjustment action abrades a power wire under the seat. There is a bulletin out on that problem, it's a simple fix when you find it. My door locks would not work once in a while and checking the fuses/circuit breakers I found the breaker for those items was hot enough to burn your finger. Check it out......I found the info on this site.........

 

[roger longman]

Hey Muddy, info on what site !? Roger.

 

[muddywaters]

The site your on Roger, CAC.......Check Recalls and Bulletins......Joe

 

[XLR8]

Roger, check out the CAC Tech Center for lots of good info:

CAC | TechCenter

CAC | Tech Center | KnowledgeBase

CAC | TechCenter | KnowledgeBase | Campaigns - Service Bulletins - Recalls

CAC | TechCenter | ModelCenter

Jane Ann

 

[roger longman]

Thanks Jane ann and Joe. Roger.