Red-brown spark plugs... Not enough fuel? - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

Gil Starr · 12-25-2001, 17:02

I've been running with the through the hood ram air for a while and have noticed that ever since I have my spark plugs have come out red-brown in color... at first I thought it was rust. I've check the cylinders when I had the IM off and found no further red-brown anywhere in the engine. This is my 3rd set of spark plugs (NGK, Bosch and Denso's).

We've checked the timing and fuel settings and all is well. Is it possible that I'm running lean when in motion due to the ram air?

I need to find an answer before I start running N20 which is eagerly sitting in my living room:s6: :s6:

Jesmol · 12-25-2001, 17:07

I had the same concerns with my straight 6 motor in an XR6 ute, I posted a similar question on the Ford Australia forum, no real definite answers, however could be due to some cylinders running slightly cooler , and maybe not burning the dye thats in petrol and LPG ( I run dual fuel)

Trey · 12-25-2001, 17:16

Additives such as octane booster and fuel injector cleaner will usually leave a reddish brown color on the plugs. Up here I see it every winter because of the stuff they put in the gas to reduce pollution.

BigProbe · 12-26-2001, 13:40

I've read where red/brown means the plug may be too hot/cool. Try experimenting w/ dif heat ranges...

Gil Starr · 12-26-2001, 17:48

If a cylinder were running slightly cooler then the rest wouldn't this be a sign that something is wrong?

I currently have been using Outlaw Octane Boosters once every month to make up for the lowered octane at the pump (93 down to 91). I've run fuel injector cleaner once every 6 months for the last 5 years, so I honestly don't think it could be the injector cleaner.

I'll try the different heat ranges to see if that makes a difference, but as mentioned before this has only happened since I started running the ram air.

Rick_96PGT · 12-26-2001, 18:25

I believe this is a coolant issue. Redish/brown color may indicate a HEAT problem.

Gil Starr · 12-26-2001, 18:43

Quote:

Originally posted by Rick_96PGT
I believe this is a coolant issue. Redish/brown color may indicate a HEAT problem.

Could you elaborate?

dmark101 · 12-27-2001, 00:16

gil, i've seen this coloring on the plugs for my probe and my mustang. most times this was attributed to additives in the fuel. i haven't seen it lately on the probe though.

one of my repair manuals has examples of the discoloration and other symptoms. i'll take a look at it and let you know.

Gil Starr · 12-27-2001, 09:01

Mike C. had one of those colored charts and we compared it but found nothing similiar to it.

I think it maybe the octane booster I've been using to compensate for the lower octane at the pump. At least I hope it is...:hrm: :hrm:

dmark101 · 12-27-2001, 09:23

i looked at my manuals and really couldn't find anything like that until i looked at my mustang book.

right as rain, there was a slightly orange colored plug. the reason for the discoloration was fuel additives. all it recommended was cleaning the plugs and reinstalling, so i guess they're okay!