I would first like to comment on the plethora of incredible information on this website, it has been extremely helpful in getting me acclimated with my Camaro.

I have a 97 Z28 with a little over 127,000 miles on it. Several weeks ago the car was just shy of the red mark for overheating. I have done some maintenance to the car's cooling system. i.e. hoses, t-stat, ECT sensor etc. I flushed out the coolant and used a prestone cooling system cleaner. I have put everything back together and the car will run great fans kick on around 220 degrees and will not overheat all seems fine but I am losing a very slight amount of coolant when the pressure gets higher (slow stop and go traffic).

After pressure testing the system around 14 psi and above there is a slight leak I believe coming from the back of the water pump that appears to be trickling down and dripping off the timing cover. I am trying to get some input as to any possible culprits that could be in the area of the water pump and timing cover. Possible freeze plug issue? Etc. I have been unable to pinpoint the exact source of the leak because it’s difficult to see but at least one of the water pump bolts looks damp.

Any guidance on what could be leaking in that area and if it’s the water pump bolt leaking should I just tighten it or with the mileage and age of the pump if it’s the original go ahead and replace it?

 

its most likely the water pump and if so its leaking on your opti. first check the thottle body. theres coolant running through the bottom part of it and sometimes the gasket will degrade. check coolant hoses going to it as well. if it is the water pump i would recomend changing the opti while your in there. once they get a good dose of antifreeze and water it isnt long before they go.

 

On the issue of the opti to which i have read extensively here, is it possible to just do cap and rotor or is it recommended to replace the entire distributor? I checked with the Chevy dealer today and for a GM opti it runs over $700. Kragen has one for $400 from Delphi. Isn't Delphi a subsidiary of GM? is it the same part?

 

only replace the opti if it's gone bad. You will get a hundred different opinions on which brand etc. It just took me 3 optis to get a good one from Delco. Quality control is terrible these days whether you pay x or 3 times x for a part.

 

summit has the gm performance opti for 385 bucks. we have a sponsor on here that has opti's for around 200 bucks and says there gm and are good quality.

 

I am debating whether to replace the opti or not because to date I haven't had any issues with it but I fully understand there can be problems down the line after a coolant leak. I would hate for the opti to go down after putting everything back together.

Another thing I noticed is in the GM owners manual it calls for GM coolant sealing tabs to be used during cooling system servicing. I have read info about this here and the consensus seems to be against adding stop leak type additives to these cars. Are these tablets from GM a good idea?

(tablets are GM part no. 3634621)

 

I hope you're not talking about us. We offer a reasonably priced alternative ($89.99 & $114.99 for 1yr 132 and 172 for lifetime) but they are NOT GM units. And if someone is claiming GM units on here for that price I'd like to know who because I've been in extended talks with AC Delco and I can assure you NO ONE is getting their hands on GM units that cheap. I told them I could move 100K a year on their optisparks and that price is still OVER my COST.

Anyways, just want to clarify. I'm all about honesty.

 

thanks, i was thinking they (the extended warrenty) were gm opti's. bummer no luck with gm negotiations yet..

 

Update on this issue:

I replaced the water pump amongst many other things and did the pressure test again only to find I had a leak in the radiator tank on the driver side. It was the original radiator and it may have been nicked during installation or transport as I took it to a radiator shop to have it cleaned and tested which it came back ok.

After a new radiator was installed this afternoon I have a leak coming from the hose running off the lower driver side portion of the radiator to the water pump. I was losing the slightest amount of pressure and as soon as I touched the hose it sprayed water. I am a little demoralized as it seems every time I fix something, something else is breaking down. I am scared to pick up the pressure tester now as I haven’t been able to get the result I wanted to date. I should be thankful because these are external leaks which are better than a blown head but still.

As best as I could tell my overheating situation was a result of a bad ECT. Since then my water pump gasket began leaking, then the thermostat housing (which was my fault from over tightening bleed screw) the radiator, and now the one hose I didn’t replace because the part stores didn’t carry it.

Is it realistic to think that the newer components of the cooling system such as the radiator hoses and water pump place more pressure on the older parts of the system like the radiator and heater hose in this case that I didn't replace causing them to fail prematurely or is my Camaro possessed?

 

shouldnt have any more pressure, radiator cap holds the same pressure in the system. just removing an old part can cause that last bit of stress it takes to make it fail. better now than on the freeway.