i8aMR2

iTrader: (1)

To all those rotorheads without cat and precats, did you notice more white smoke or condensation upon startup and idling while cold?

Also, do pre-1988 cars have cold start assist whereby some coolant is injected into the combustion chamber? I did a search and some ppl mentioned it but it still doesn't make sense to me.

Problem?...I'm looking at a car that smokes white when cold and owner says it looses coolant. I almost concluded that the water o-rings are probably worn (need rebuild), but I want to make sure if there are any other factors before I spend $70CDN on a compression test to find that out. The car appears to pull ok

Thanks

eViLRotor

iTrader: (2)

Yes, the cold-start assist injects coolant into the throttle body from a reservoir on the firewall on the passenger side.

Both my 7's have smoked on cold startup. My current TII, no cats and pre-mix, smokes like a mother. Smoke is more blue than white, though.

Problem is, its really hard to tell the difference in the winter when all cars smoke like mad.

i8aMR2

iTrader: (1)

What's the function of the coolant though? So I assume the cold start reservoir sucks the coolant fromt he main one?

So, I'm going to assume that pre-1988 models naturally lose some coolant overtime and must be topped off.

Anyway, I've decided to have the car compression tested. Mike says the car's coolant was boiling, then he had to top it off, then top it off a few more times on his drive back to Toronto from Calgary. Doesn't that mean permanent damage??

i8aMR2

iTrader: (1)

Mike said that when he was topping off the coolant before he left Calgary, he didn't take off the rad cap but he only took out the air bleeder screw. He says that therefore there were air pockets in the system and the air bubbles would heat up and and cause the coolant to boil. I haven't heard that before. Why wouldn't you take off the rad cap then? Any ideas?

WookeysRX7

NEVER TAKE OFF YOUR RAD CAP WHEN YOUR ENGINE IS HOT!

WookeysRX7

NEVER TAKE OFF YOUR RAD CAP WHEN YOUR ENGINE IS HOT! Your cooling system us underpressure at all times when the engine is hot so if you open that rad cap whe the engine is hot, you gonna have coolant burnin your lil face off and coolant all over the place too. Think about it, when stuff heats up it wants to expand, hence the pressure build up. Pressure is a normal thing in all cooling systems. If not then wtf is wrong with your car?! haha

Cameljoe

well you never want to take off the cap when the car is running cause coolant is hot. because the contents is under pressure. the screw has a tiny opening whereas the cap is larger letting more hot coolant out. I knew a kid who didnt know that. opened the cap while the car was running and got coolant burns on the his face, neck, shoulder and hands.

eViLRotor

iTrader: (2)

Actually no. The cold start reservoir is self contained. It does not feed off the regular coolant. In fact, its supposed to contain 90% antifreeze/10% water.

What exactly the coolant does in the throttle body...beats me.

I'm pretty sure that the coolant loss is not natural.

i8aMR2

iTrader: (1)

So where does the coolant come from then? Natural, meaning that it is burnt off when injected in throttle body... I dunno.

i8aMR2

iTrader: (1)

Well obviously I know you shouldn't do it when it is hot, but why didn't he do it when it was cold?

YakATK

Yeah my car smokes a bit when warming up too. I got no cats on my car and for about 1-2 minutes you get some white smoke out the tailpipe if it is cold out and your just starting the car. Most cars have extra thick exhaust when warming up still so seems normal.

eViLRotor

iTrader: (2)

My guess is that if the car is losing the main coolant (not the stuff in the cold start reservoir) and there are no visible coolant leaks, then the water seals are probably going bad...

i8aMR2

iTrader: (1)

Hey. No, I mean where does the coolant in the cold start reservoir come from?

AreExSeven

From you pouring it into the reservoir

Cameljoe

The cold start has its own reservoir. Its a small container on the firewall on the passenger side of the engine bay.