This is my first post here. Thanks for a great board guys.

Recently, my ’95 Tahoe with 67K miles got a SES light that my dealer coded as a malfunctioning EGR valve, so at his suggestion to save me some bucks I cleaned it (soaked it in my gun cleaner Ballistol overnight), and put it back in only to have the SES light come on again 2000 miles later. I think my problem is that I “baby” my engine by keeping revs to a minimum, and with a lot of around town driving in overdrive, I’m assuming I get carbon buildup in the top end of my engine including that pesky EGR valve.

I was going to use a top end cleaning chemical to clean her up, but did a Google search first for ‘Top End Cleaning’ information, and found a Ford truck board where someone suggested running the engine up to at least 4000 RPM for a mile about once a week, and that method will clean the engine free and easy.

So off I went down the interstate REDLINED at 4000 RPM in 2nd gear (about 55 mph) for a mile and got off the next exit to go home. I kept the AC and radio off while redlining so I could listen for things coming apart, but only heard a tight engine and screaming tranny gears. During the redline mile my water temp gauge moved from 180 to 200 degrees.

Well, all I can say is that I don’t remember my 350 TBI running as smooth as it does now [img]images/graemlins/smile.gif[/img] No SES light coming on (at least not yet) and it idles smooth as silk at traffic lights (no more intermittent misfires). The hot gas cleaning method must work because I noticed the inside of my tailpipe is as clean as the outside where it used to have that black carbon coating, so I’m assuming the top end of my motor is just as clean.

Here is the link to the Ford board discussion of top end cleaning FYI.
http://www.ford-trucks.com/forums/sh...hreadid=124900

What I probably should have done first, and will do next is find a Ford Expedition/F-150 to peek into and see if 4000 RPM is redline for that engine. If it isn’t, the next time I do this I’ll probably lower my RPM’s to 80-90% of redline rpm’s, because it seems to have cleaned up so quickly that I probably didn’t have to strain the motor and run the revs up so high.

Anyway, has anyone else here tried this top end cleaning method? I never heard of it before, but it made sense to me, and it appears to have worked great. Again, thanks for all the great info on this board.

Umm..... I want to make a bad Ford joke, but I think I will refrain...



The only thing I think I can say is........... ow. [img]images/graemlins/shocked.gif[/img] [img]images/graemlins/thud.gif[/img]

Yep, seen it a million times. Another good thingto do is get on a long downward slope where you can accelerate to about 55-65 mph going down hill then just let off the gas and let it compression brake a little. This will cause whats known as cylinder wash down and help clean some stuff up to. But yeah get out on a highway in the hills some where and drive it like a race car once in a while. Floor it around turns, take off fast, etc. Hard on tranny's but it does wonders for engines...

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Hey, its good to hear that cleared your problem. My ses light comes on now on the freeways, but i've been unable to get the codes read with a paper clip, and now that i'm off at school i will probably deal with it when i go home.

I've never run my truck at that high of an RPM for that long, but i definitely drive it hard for time to time (i AM still only 18) [img]images/graemlins/smile.gif[/img]. Too bad i have to be careful now that my tranny is going out [img]images/graemlins/crazy.gif[/img]
But the motor just rolled over to 100k a little while ago and its still running strong [img]images/graemlins/cool.gif[/img]

Get to autozone and get that code read. It may be an o2 sensor going out which could cause bad mileage and it could also cause your engine to run real rich and kill your cat...

Also could be a ton of other things that could cause bad bad problems if left unchecked...

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ayee, that'd make me pretty nervous - redline for a mile [img]images/graemlins/crazy.gif[/img]

Darren, its takes all of a minute or two to read the codes. if you can't do it with a paperclip, go to autozone and get a little code key. fyi, it does the same thing the paperclip does, it just looks prettier [img]images/graemlins/grin.gif[/img] whenever you get home from school, right before you shut your door to walk inside, just lean down and stick a clip in there and turn your ign key on and watch the dash...when you get the codes, turn your key off, pull the clip out, grab your backpack shut the door and walk inside.

haha, its not that i can't do the paper clip thing. It just flashes fast and i haven't been able to count it. Never dawned on me to put the paper clip in there and THEN turn on the key though..... [img]images/graemlins/smirk.gif[/img]
I always turned on the key, tried to stick the paper clip in, and watch the dash at the same time [img]images/graemlins/thud.gif[/img]

I will try it again now, but i won't be around the truck til friday (freshman doen't get permits, have to park off campus), so i'll let you know the codes then.

Damn i feel like an idoit now, haha
Ive had a few things on my mind getting ready for school.....i was so out of it, i parked my truck for the first week under a tree that sapped the ENTIRE truck
[img]images/graemlins/frown.gif[/img]
So needless to say i now know where the self service wash place is.....

lol well, each code will flash three times, so you can catch it on a repeat. what happens is, you stick the clip in, turn the ign key to 'on' and watch the SES light. it will flash once, pause, then flast two times...that is a code 12, which just means user interface. it will repeat that code two more times. then, then next code that flashes will be any trouble codes set by sensors. an EGR for instance will flash three times, pause, flash two....and it will repeat that sequence two more times.

so, don't worry about missing the codes, it will continue to repeat over and over until you turn the key off or pull the clip out. you can let your codes run until you kill the battery if you wanted [img]images/graemlins/crazy.gif[/img]

Thanks, i just printed out the thing from autozone on reading codes again. I had the truck running when i did it too, and so it just flashed like 15+ times in a row and did some other crazy $hit.

So what genious at GM decided to get rid of this feature in the OBDII trucks?

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