I am trying to track down a problem with my motor where I am burning coolant on hot restarts (run motor until it is hot [20 mins+]), shutdown, restart right away. I get white smoke out the exhaust pipe and it smells like coolant. Did compression check, it is good (220, 212, 215, 220).

What I am confused about is how the coolant is getting into the cylinder. I've read somewhere that coolant flows into the head or the intake manifold to warm it up during cold starts or something. I know Hondata makes a gasket that blocks coolant flow somewhere near the intake manifold? Can someone clue me in as to where the coolant is actually going? I am thinking that coolant is getting into the cylinder via the head or near the head.

Thanks

 

More info:

If I let the car sit for a while and the motor cools down, no white smoke at all. White smoke only appears for about 3 secs on hot restarts, then it goes away and can't smell the coolant in the exhaust.

Yes, I am loosing some coolant, but not much. No frothy stuff under the oil cap. No oil in the radiator. Check around the block, no leaks.

Recent change: 1.6bar radiator cap (stock 1.1bar was broken and radiator was boiling over)

Coolant temp never went past middle. Oil temp never got over 230F.

 

OK from the radiator the water goes to the pump that pushes it in to the space between the block and the sleeves, then it goes in to the head and a bunch of cavaties some connect to the tb and a lot of other places its really amazing how they do it. Is your car running funny?


[Modified by Therumblingteg, 8:54 PM 3/16/2003]

 

Maybe bypass the throttle body coolant lines? I think thats the only place in the manifold that coolant runs.

 

No, car runs strong and not having any problems, except for the white smoke during hot restarts. Does coolant actually go into the head? Isn't the head mostly oil "cooled"?

 

Ahh I think that may be it. So there is a coolant like that circulates coolant into the tb to warm it up, or does it circulate it into the head on the intake side? I don't actually see any lines where the coolant would go into the intake manifold.

I suspect that make I broke a seal or something in the TB and when the car is hot and the coolant system is pressurized at 1.6bar, coolant is getting in via the intake and then into the cylinder.. and that is why on hot restarts I get white smoke.

 

Yes the water most defeneatly gets in the head. Then back in the radiator. It could also be your intake manifold gasket.

 

OMG!!!!!!!

so much incorrect information in this thread!>?!:!":!:>

let me provide some reality here:

the head has coolant (not water) circulating through it to cool it.

oil is NEVER used to cool and engine.

the coolant that flows through the TB would NEVER get anywhere near the inlet tract.

the coolant flows through the IM at the distributor end, from the thermostat bypass port of the coolant system (big U bend hose)

(Hatchy have you actually looked inside your engine bay at all the pipes, hoses, wires and stuff???)

<u>i reckon you have a very small leak in the head gasket.</u>

that is really all it could be...

see if there are any bubbles in your coolant overflow tank whilst the engine is running...

also pull all the spark plugs and look at each one.

one may have a very black shiney wet looking tip, whilst the others will be a black sooty dry tip...

t..

PS a compression test will not tell you about a slight head gasket leak

 

Yes, I've looked but wasn't sure if the coolant flowed via some passages inside the block/head. When I pulled the plugs, all of them looked okay, none of them where shiney or wet. There were all nice and dry, and a darker soothy color.

There are *no* bubbles in the overflow tank when the motor is running, and no oil in the radiator either (and running with the radiator cap open for about 10 mins, I didn't notice any bubbles either).

How can find a small leak in the headgasket? leak down? Why would it only smoke when the motor is on a hot restart and stops a few secs later?

 

just be paitient - it might get bigger... LOL!

anyways, from what you say, no coolant is getting into the cylinders...

maybe it is OIL. a whitish blue smoke.

maybe from the PCV system?

dunno.

if it gets worse - then you might start to worry, but now as it is not affecting performance, dont stress...

t..

 

Well, I am going to replace my turbo and will be running bigger boost (~20psi), so if there is a problem, I want to get it resolved now, not later

It is definitely not oil, I know what that smells like (my old BMW use to burn oil) and it is definitely coolant. I guess I could try a leakdown and see if I see bubbles in the radiator at 100psi? Also thinking about pressurizing the coolant system at 30psi and see what happens.

 

for the record all the stuff I said is valid execpt for the water part, ofcourse water and coolent are accosiated.

 

no problem

for the record you should avoid using water as coolant, unless in emergencies...

t..

 

check and check, thank you

 

I agree

Ummmm, yeah I'm going to have to disagree with you on that one...

Oiler coolers do provide a means of cooling an engine. The oil is heated up from the combustion process. When an oil cooler is used, some of the heat that was added to the oil is extracted and the oil enters the engine at cooler temperature than it came out at. Heat is again added to the oil as it circulates through the block and as it again passes through the cooler the oil temperature is again reduced. The temerature gain of in the oil is from the engine. Therefore the oil is extracting heat from the engine and essentially cools the engine. While the heat extracted from the engine due to cooling the oil is much less than that of the coolant, it does nevertheless cool the engine. There for oil CAN be used to cool an engine.

 

no.

the role of oil in the engine is to lubricate, not to cool.

if oil is cooled by an oil cooler it is to cool the oil not the engine.

the radiator is used to cool the engine, not an oil cooler...

oil is NEVER used to cool an engine.

(however - it may, by the use of oil coolers, get cooled and subsequently reduce the temprature of an engine by a fraction of a percent...)

additionally, it may be used to cool turbos...

t..

 

I've never seen oil being used as the main coolant; but like you say, it contributes a little bit. Spraying oil on the underside of pistons is for local cooling, not really for lubrication. Some turbo bearings are water-cooled, some just use what cooling they can get from the oil.

Back to the original question...
Maybe there's a leaky gasket letting coolant leak into the intake manifold. That would explain why it doesn't look like a headgasket leak. When he starts back up pretty soon the "water" is still there. If he shuts down for several hours it can evaporate.

 

Jim,

What is the easiest way to check if the gasket at the intake manifold has a leak?

Thanks

 

You could wait till maybe 1/2 hour after shutting off the engine; take off your intake pipe & smell for anti-freeze. If you try to get in there with a rag or something, you can check if it gets wet with anti-freeze, but you'd be SOL if part of the rag got stuck in your manifold...

Or pressure-test your cooling system. There's some kind of funny fitting goes on in place of your radiator cap, allows you to pump up the pressure without the engine being hot. Then take off your air intake pipe & see if you can look into your intake manifold. The trick way is to use some kind of borescope to look around in there. But if it's leaking you would probably be able to smell the anti-freeze.

Even if you can't see in there, if your system holds pressure properly, then you know that you don't have a coolant leak anywhere. If you look for leaks when the engine's hot, often the coolant will evaporate immediately & you never see it.

It may even be easier to just take off the manifold & get new gaskets??