I have been trying to diagnose a problem with my motor. during cold start it rough idles about 10-15sec, I ran to the back of the car to see if I can smell anything sweet. It does have a hint of it. So I know there is a leak somewhere into the motor. It's specially more noticeable when the car hasn't been started for 2-3 days, longer rough idle and more smoke. But its fine after a bit.

My question is besides a failing water jacket seal is there another possibility that coolant is getting into the engine another way?

I plan to replace the thermostat, hoses, and the reservoir one of these weekends (when all the parts are here) is there anything else I can look for. I have smoke machine I plan to smoke the whole radiator path when drained. I have smoked the reservoir and I already know I have a cap leak.

 

Can't think of one. Sounds like pretty textbook water seal failure.

What will smoking accomplish? The coolant system is pressurized, if there is an opening somewhere visible, the hot green spray should be pretty apparent in ways smoke isn't.

 

Depends on the amount and location(s) of coolant smell. It's possible to have a slow external leak, and then the fan blows it around and makes it smellable toward the rear at startup. If that's the case, the engine bay will smell of coolant. If it's going through the engine, you'll only smell it in the exhaust. About the only ray of hope I can think of though.

 

Smoke testing wont really tell you much unless you have a leak that is shooting somewhere in your engine bay. Even after draining your radiator, your engine will remain mostly full of coolant.

• Does your car still have a cat? Typical coolant seal issues are not only the smell, but pluming thick white smoke on cold starts.
• Another check you can do is let the car sit for a few days. Hold your Accelerator pedal to the floor, crank the engine for ~10s, and then take the plugs out to see what they are wet with. Oil = rotor oil control rings, gas = injectors, coolant = coolant seals

Autobahn88 has a silicone hose kit off of amazon that I have not had any issues with. Although they sell everything in 2 different kits for some reason. One of the kits include the engine to heatercore hose on the left side of the engine. (these tend to balloon and burst after 80k+ miles)