Just purchased 97 cobra

[ml504]

Just purchased the car and currently has 138,000 miles and I’m looking on advice on where to start working the bugs out. This is what I know so far:

1. Car has a knocking noise but doesn’t sound like it is an internal engine, almost sounds like something is loose. Higher rpms and it goes away. Any ideas on where to start looking?
2. Clutch has vibration when depressing, very stiff going into any gear. Is it time to replace?
3. Check engine light has been disabled by a previous tuner so I’m not even sure what codes are being thrown (said it was disabled to pass emission test). Not much info was given. What is best way to get back to basics to know what is going on?
4. Local shop did a smoke test and said it was leaking at intake due to a possible crack. Is this common/what is best option?

I know it is a lot of questions at once and I hope to get some more time this week to get more info, I just need some basic starting points from people who know these cars as I’m kinda starting blind not knowing the history. The car has 4.10 gears, long tubes, maybe pulleys but is otherwise stock from what I’m told.

Thanks,
Matt

 

[jgt58]

Said noise. Does it do it at idle without the clutch pressed in? Does it go away once the clutch is engauged?

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[98 svt]

3.) Do you have an OBD2 scanner?

4.) Not sure about the intake crack. Maybe a bad gasket/poor seal after someone had the intake off to clean the IMRCs.

 

[scottydsntknow]

Just purchased the car and currently has 138,000 miles and I’m looking on advice on where to start working the bugs out. This is what I know so far:

1. Car has a knocking noise but doesn’t sound like it is an internal engine, almost sounds like something is loose. Higher rpms and it goes away. Any ideas on where to start looking?
2. Clutch has vibration when depressing, very stiff going into any gear. Is it time to replace?
3. Check engine light has been disabled by a previous tuner so I’m not even sure what codes are being thrown (said it was disabled to pass emission test). Not much info was given. What is best way to get back to basics to know what is going on?
4. Local shop did a smoke test and said it was leaking at intake due to a possible crack. Is this common/what is best option?

I know it is a lot of questions at once and I hope to get some more time this week to get more info, I just need some basic starting points from people who know these cars as I’m kinda starting blind not knowing the history. The car has 4.10 gears, long tubes, maybe pulleys but is otherwise stock from what I’m told.

Thanks,
Matt

1 - Gotta be more specific. Where does it sound like it is coming from? Can you make it go away with the clutch? Have you taken a long screwdriver and used it as a "stethescope"

2 - Yes, clutch, flywheel, pivot stud, fork, throwout bearing/pilot and possibly the cable. If the cable is not an OEM cable then it needs to be replaced regardless. If your engine is actually borked and it isn't just something loose, the good news is pulling the engine makes it really easy to do the clutch lol.

3 - The handheld should have come with it unless it has a chip. If it has a chip and its otherwise just a bolt on car I'd remove the chip and go from there. If its tuned by a handheld then hopefully you have the handheld and can flash back to stock.

4 - At the intake manifold or at the tube? More specifics?

 

[ml504]

Thank you for the replies. I will try to get some more info on the noise but I don’t believe pushing the clutch in affected it. The car must have a chip because no handheld came with it. I have attached the only service record that came with the car so maybe this will help some. Thanks again...

 

[98 svt]

Thank you for the replies. I will try to get some more info on the noise but I don’t believe pushing the clutch in affected it. The car must have a chip because no handheld came with it. I have attached the only service record that came with the car so maybe this will help some. Thanks again...

Wonder why the shop didn't pump out the old fuel he kept mentioning in the invoice.

 

[jgt58]

That invoice is crap. 138 bux for new plugs and labor????? I'd say your lower intake gasket is not correct and causing the leak thus making your fuel trim lean

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[Shifty Powers]

Did the prior owner say how the CEL was turned off? By a tune? Did he give you the tuner?

 

[ml504]

I believe he said turner but I could be wrong....any tuning other than a chip would have been done at a shop as he said he never has owned a handheld. What is the best way to tell if it has been unplugged (if yo7 can do that?)

 

[scottydsntknow]

If there is a chip it'll be on the actual computer, like actually piggybacked onto it and then likely duct tape over it to close off the case. But if you tune with a handheld or have a shop plug in and tune without a chip it just overwrites the stock tuner on the ECU. Hopefully its just a chip, then you can just unplug it and call it good. That's what happened to the 00 GT in my signature when I first plugged into my SCT it told me to go toss off. Went and pulled the ECU out and sure enough there was a chip on it.

TBTH I hope you got a really good price on the car to the point where if the engine or trans (or both) is blown you still come out ahead. If you don't know about these cars I probably would have passed and gotten something stock or close to stock from an owner who actually knew wtf was done to the car.

 

[ml504]

Thanks, I am going to try and get some time this weekend to really start looking at some of this. I don’t think it’s as bad as I’m making it sound, I’m just trying to establish a baseline of where to start and get familiar with what I’m working with. As far as price, I have below $2000 invested including tax so I have some wiggle room. The car was about to be traded in and I happened to be there and bought it on the spot. Thanks for the info.

 

[scottydsntknow]

Running and driving with no rust for $2k is great. Figure out the computer and then go from there.

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[ml504]

Wanted to post an update. I’ve had time to read up and familiarize myself with the car and am getting some answers. I pulled the intake off and everything including gaskets looked good. The IMRC plates were dirty but not sticking and I tested the control box using an ohm meter and instructions found here on a prior thread. Looks like the vacuum leak was actually from the o-ring that the rod that the butterflies are attached to. Once the new bearings and O-Rings come in I can put it all back together and start addressing the next issue.

I also found out it was never tuned by handheld just had a chip installed. This poor car was neglected to say the least. I’m looking for a stock air intake or best aftermarket that does not put the filter inside the fender well. I don’t know how long this filter has been this way but I’m guessing this in itself was causing a noticeable power loss.

Thanks for the replies and advice on the car.

 

[9397SVTs]

You actually want to place the filter inside the fender well area, not inside the engine bay. Unless it's damaged, that filter can be cleaned and used.

 

[98 svt]

Just go back to an OEM air intake, and use a drop in K&N. That's pretty much your best bet.

 

[jgt58]

Just go back to an OEM air intake, and use a drop in K&N. That's pretty much your best bet.

That's why I'm putting this intake in the snake. Gonna get some plexiglass cover for it

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[Tillerman77]

The IMRC plates were dirty but not sticking and I tested the control box using an ohm meter and instructions found here on a prior thread. Looks like the vacuum leak was actually from the o-ring that the rod that the butterflies are attached to. Once the new bearings and O-Rings come in I can put it all back together and start addressing the next issue.

Take some photos of the O-ring replacement on the IMRC plates if you can. That is one maintenance procedure that doesn't have too many "how to" threads that I have seen.

 

[ml504]

Take some photos of the O-ring replacement on the IMRC plates if you can. That is one maintenance procedure that doesn't have too many "how to" threads that I have seen.

Will do. Here are some before and after pics of the intake.

 

[Tillerman77]

Good progress and photos. As you might imagine, adding an oil catch can would be a good idea once everything has been cleaned.

 

[ml504]

Started putting everything back together. Blasted and refinished crossover pipe and rebuilt injectors.