I have a 2000 SSEi. When I stop at a stop sign, sometimes I seem to get a whiff of coolant when I stop. I have searched everywhere in the engine bay and can not find any external leaks. The exhaust pipe doesn't seem sticky. It doesn't seem to be using any coolant (I've had the car less than a month though). From reading here, it seems that the intake manifold gaskets fail on these engines frequently. Would any of you say this is an early warning sign of that?

Would a tube of that silver seal pellets/powder placed in the radiator help with this?

HEater core maybe?

<<Would a tube of that silver seal pellets/powder placed in the radiator help with this?>>

Would not hurt. Might help.

Those "slight whiffs" are tough to troubleshoot. Mine did that. I started searching with a small mirror and strong light. Found that my radiator cap would seep off a drop or two, then dry right back up. A very close inspection revealed a very slight dried trail of anti-freeze down the front side of the filler lip. A new cap solved that one.

Before I put in a commercial product sealer,...

Have you changed the antifreeze in the car? When you did, were a couple of pellets of the GM'* antileak put in?

I have an 03 and it had the recall for bolt modification on throttle body and when they did it, they put in 5 pellets of crushed (organic material) from GM that will seal seeps. They leave a brown color in overflow so GM had left them out to impress new car buyers.

But I read that when draining antifreeze at 2 years for changing, the antileak needs to be refreshed. So I bought a pack and have put in two every time I drain and change antifreeze at home.

Stop at your Pontiac or Gm dealer for them. There'* a version for Northstars and a different version for other GM motors; be sure you get the right ones.

I haven't changed antifreeze. It looks fresh though, so I think dealer must have just done it. Thanks for the suggestion though. I'll check into that.

I wouldn't aim for any sealers until I found a leak, determined it to be small.

A heater core leak will usually leave antifreeze film on the windshield.
Check for a leak where the coolant elbow enters the lower intake and accessory bracket.
Check under the throttle body for any leaking
Look at both black plastic endcaps of the radiator (to the best of your ability) for leaks/cracks.
Check where each hose is connected for any signs of leakage

For you to smell it, then it is leaking somewhere in the engine bay or heater core. The key being externally.. therefore you should be able to find it. If the engine is a little dirty..a cleaning will assist in finding the problem area.

Yes, this coolant leak and/or smell has me stumped. I have looked all over the engine compartment three different times. There is no coolant anywhere. There is a little oil on the rear cylinder head, but it is very minor. I've checked hoses, radiator, cap, everywhere.

There is no coolant in the cabin...like what typically happens if a heater core fails. There is no coolant on the garage floor.

The thing that is weird is that I don't notice it until I stop at a light. If it were a constant leak in the core, or somewhere else in the engine compartment, I would think that I'd smell it all the time, not just when stopped.

I've marked the ouside of the coolant recovery tank. In three weeks, it may have gone down 1/16 to 1/8 inch at the most. It is hard to tell if it went down at all.

Back a few months, another member had a similar problem, and posted this thread on what he did during his search.

http://www.bonnevilleclub.com/forum/...131&highlight=

I don't believe that he ever reported finding it.

Have you pulled your plugs to look at them?

I assume the engine block is clean and free of any excess coolant that may have been bled under the engine cover onto the top of the block?

Reason I ask is every time I bleed the system..I wash down the motor to get the excess coolant off the engine. Otherwise I end up smelling it, even long after it'* dry and burned off.