I have thin layer of white powder thats visible down my exhaust pipe. I think its because the car is running to lean. All I have is HKS Catback and HKS downpipe. Any ideas as to how to fix the problem? Any help would be great. Thanks.

 

Is it on the outside of the pipe?

Either way it sounds like you may have a little coolant leak that is streaming down the underside of the car/and exhaust. Try looking at the heater hose and turbo coolant lines. There are 2 turbo and 2 heater hoses on the passenger side of the car.( In the turbo/firewall area)

how is the level of coolant? Any issues with that of late?

 

what kind of gas are you running? Lead does that to the inside of exhaust pipes

 

i use 91 pump gas all the time. The white powder isnt visible on the tip or inside the tip, its just straight down inside the pipe. When I pull out my coolant dipstick, it's covered with a whole bunch of brownish sludge. I just changed the downpipe today and inside the stock one theres a little bit of the wite powder too. Car has been running fine though. Heres a pic of the exhaust pipe from the back of the car:

 

Try running 93 octane instead of 91

 

its hard to get 93 down here in SD. But u guys think for sure the problem is the fuel?

 

Kinda look like this?

 

I doubt it's the fuel. Everybody gets 91 in California and you don't hear about anyone complaining about this problem. I'm w/ Dave and inclined to think it's a coolant issue.

 

yeah it sorta looks like that in the stock downpipe.

 

Could it be the pre or main cat decomposing? Just a thought.

 

Anthrax!

 

HA! That's great.

Lean stoich or coolant is getting into your exhaust.

BTW, if you wanna get rid of that nasty baffle in your HKS, I did a write up on getting it out. I was so proud of it, but I'm not sure anybody's really gotten inspired to do it by me. Check it out:

https://www.rx7club.com/showthread.p...ght=HKS+baffle

 

I know I asked earlier but didn't see a response.. Are you having any coolant loss issues? Smelling any sweet aromas?



Speedking- I think the reason not a lot of people complain abot this is that not many take off the turbos to see the manifold ( i know that was someone else, not the original poster) or they don't look up the exhaust far enough.

Also usually Most people don't worry about things until There is evidence of a problem. ( kinda ties in with nobody looking into the exhaust)

 

I found white powder on my Downpipe too. Does anyone find out what cause the problem?

BC

 

are you saying the dipstick in the coolant reservoir? I just wanted make sure I am thinking the same dipstick.

i would check for cross-contamination (ie coolant in your oil, and oil in you coolant).