Ever since I installed my jdm d15b I could smell coolant burning in the tail pipe. I only had to add coolant once, it lost very little... but it stunk!!

So before I tore the engine apart I checked EVERYTHING.... leakdown, compression, cooling system pressure test, checked and cleaned IACV, spark plugs, monitored oil and coolant levels... everything was perfect

Removed the intake and head today....

tops of pistons (not even touched): very clean and normal looking, no obvious coolant burning.



combustion chambers: a little rich because of the P28 ECU, I will be taking care of that. Notice the #3 intake valve is a little more discolored?


still no obvious coolant burning, looks normal. little rich, but normal.


Now the intake manifold: ICK!!! How did that happen? It was in all the intake ports. This motor only has a few thousand miles on it... DEFINITELY should not look like that.

So I put everything back together with new gaskets and everything cleaned up and it runs better (smoother), but I dont feel like I cured the problem.

And to brag: I drove the car home from work today at 5, and had it running again at 7:30, then did the timing belt.

Any help or suggestions? Thanks.

 

meh

 

are you sure there is coolant burning from the exhaust. doesnt sound like there is a leak, and judging by the pictures it looks ok. usually a leaking headgasket will clean the carbon off the piston and chamber very noticable.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Runnerdown &raquo;</TD></TR><TR><TD CLASS="quote">are you sure there is coolant burning from the exhaust. doesnt sound like there is a leak, and judging by the pictures it looks ok. usually a leaking headgasket will clean the carbon off the piston and chamber very noticable.</TD></TR></TABLE>

yes coolant is burning in the exhaust. im wondering why the intake port looked like that.

 

I see motors with deposits like that when they are usually driven around the city or for short periods of time. no worries

 

but the exhaust ports are cleaner (and drier). i drive the same conditions with all my cars and none of them looked like that inside the intake ports.

 

you said it was a jdm d15b. it was probably like that when you got it.

 

Are you talking about the brownish valve?? Because that is your exhaust valve not your intake valve. From the pictures i can't see any discoloration in the intake valves. Your fine I've seen that on many exhaust valves like that and the engine ran perfect.

 

im not worried about the valves, look at the intake ports. they are filled with wet black GUNK.

 

that is from the pvc system. Oil blow by from the crankcase and valve cover is rerouted through your intake system for emission purposes. Thus oily residue builds up in the intake manifold. That is normal to an extent.

Is that how every intake runner looks or just on the 4th cylinder in the pic?

 

all of them are like that. and i think you are right.... the pcv appears to be clogged.

 

yeah i was about to say check all of your pcv system for clogs... of a MI member

 

its still freaking burning coolant!! AAAHHH!!!!

 

is there ANY OTHER WAY coolant can be getting into my combustion chamber?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ham &raquo;</TD></TR><TR><TD CLASS="quote">its still freaking burning coolant!! AAAHHH!!!!</TD></TR></TABLE>

Are you sure its coolant and just not condesation. Looks like steam coming out of exhaust. That is normal as H2O is a natural byproduct from the combustion of Hydrocarbons (gasoline mixed with o2). Make sure it not that, cause i fooled myself to thinking it was coolant when in reality it was just condensation. Also happens when its colder out, just like when you breath out you see your breath. Hot air hitting cold air.

 

NO, its burning coolant... it makes people inside my car cringe when it comes inside the windows. its definitely coming out the tailpipe. i figured this out months ago. just today the inside of my car smelled like burning coolant because i had the windows down. i just need to find out HOW coolant is getting into my combustion chambers or exhaust.

 

I'm confused. You say that you figured this out months ago, that you only added a little bit of coolant and you had verified all the fluid levels were ok. If it were burning to the point where it smells so much and is clearly coming out of the exhaust, the level would drop dramatically. Also, a telltale sign of burning coolant is a very clean, carbon free cylinder. All of yours look pretty good and even. It just doesnt add up to me.

 

My .02 cents. It's a hole in your exhaust somewhere. Could be obvious, or it might be on the top of the exhust pipe somewhere (happened to me). I figured that when the condensation and exhaust deposites mix after the car has been ran for a bit then shut off (more so in colder areas) you get that coolant smell form your exhaust. Also since you say people cringe when they get in the car, the motor checks out fine, and you determined that the smell is coming from the tailpipe. I'd give the whole exhaust a once over... ie: take it all off and inspect it. Again just my .02 cents. Goodluck though

 

i took out the #1 spark plug and i could smell coolant. its very intermittent. my friend and i were looking at it for like an hour. went driving around, looked at it, sniffed around... nothing. then 5 min later i could smell burning coolant, went and stuck my nose over by the tail pipe and sure enough, thats where its coming from.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Runnerdown &raquo;</TD></TR><TR><TD CLASS="quote">I'm confused. You say that you figured this out months ago, that you only added a little bit of coolant and you had verified all the fluid levels were ok. If it were burning to the point where it smells so much and is clearly coming out of the exhaust, the level would drop dramatically. Also, a telltale sign of burning coolant is a very clean, carbon free cylinder. All of yours look pretty good and even. It just doesnt add up to me.</TD></TR></TABLE>

its very little. there is no (visible) smoke and ive only had to add coolant once. I can see my recovery bottle level slowly dropping. i believe the cylinders look normal because theres hardly any going through. what i figured out was that its coming from the tailpipe.

 

maybe it was burning coolant and the head gasket and intake fixed it, but there is still some burning out in the exhaust. (crosses fingers)

ill wait it out and see what happens.

Thanks for all your input.