93 Mods? Need some help....

[keplinger78]

Hello All,

Well I have a 93 with 285,000 miles.It's getting the 4L80(junk) rebuilt as I type.So the tranny problem will be fixed or the 12 month 12,000 mile deal will get it fixed again...LOL. I have only had it about 1 1/2 months and have drove it maybe 400 miles....No reverse,overdrive sometimes slips,smokes when cold,seems to have blow by on PCV valve(which is not connected to turbo tube) and blows a little oil on the engine...I didn't do it!!! The guy I got it from was a diesel mechanic for a trucking place,he said it needed a head gasket,he even gave me the new gaskets.He gave me a set of heads,heck I can see the crack between the valves...He said that didn't hurt them???I have built a lot of gas motors.This is the first diesel i have owned,I think the extra heads are junk.

So here are the problems...
1) It smokes a lot at start up,I have put a new controller on it (that helped)and have new glow plugs on the way from SSDiesel Supply.But can a head gasket cause this? I will get some injectors when I get more cash freed up.

2) It now seems to be pushing water out the overflow...BAD Head gasket
I have the gaskets and just waiting for it to come back from the tranny shop.
If they have any cracks I don't want to reuse them.He said it has never been hot,so they should be fine.It has never been over 210 when I have drove it,longest was about 60 miles.

OK after I get these problems fixed I want to do some little mods,Exhaust& Air filter, But I can't find a chip for the 93,I have read where you can turn the fuel up on this pump to get more power from it?How???? I will be using this truck as a welding truck 5 days a week and a racecar puller on weekends so it will get a workout. The tranny shop is putting a HD cooler and torque converter,some kinda HD shift kit it's costing me a lot @$1600 to have the tranny fixed,but the cab is great and I traded a wrecked vette for the truck.So I can afford to put some money in it to make it right.I'm putting a steel flat bed on it and a Lincoln Ranger 8 gas welder.I'll try to upload some pics,before and after etc.

Thanks for the help,

Tom K.

[Mtrman]

I would get that head gasket changed ASAP. The small creaks between the valves may not be an issue. I would have a machine shop pressure test them to make sure. My heads had the cracks on #8 cylinder. It pressure tested OK , but when the machine shop went to clean up the deck they ruined 2 of the pre cups. Clearwater cylinder has new heads for around $640 a pair shipped. I put a set on my truck and I have not had any issues with them. The valve cover gaskets Yes, the heads No. While you are into the motor you should change the timing chain. If it is the original with 285,000 it is a ticking time bomb. I also would recommend a H.O water pump. I never even run 200 even with the AC on and towing.
As far as Mods on a 93 there is no computer so there is no chip. You can do intake, exhaust, mechanical boost control, and turn up the injector pump. Before you do this get a pyro gauge and a boost gauge. If not you take a chance of a melt down. I have not turned up my pump. I have read articles on how to do it, but I am having a brain lapse and can't remember were I read it. I will try to find it and let you know.
As far as the smoking on start up does it do it all the time or just in the morning on the first start of the day? My truck would start and run great for about 5 seconds and then spit, fart and smoke for 15 seconds. It turns out that it was running out of fuel. The oil presure switch was not seeing oil quick enough, on the first start of the day. You can test this with a paper clip at the fuel pump relay.
you will enjoy the 93. They are dependable when GM started using the electronic injection pumps in 94. It gave the 6.5 a bad rap
Mike

[keplinger78]

Hello,
Thanks for the reply,I plan on fixing the head gasket when the tranny shop gets the tranny fixed....been two weeks now....its getting put back together.the servo piston for OD was cracked,clutches burned to crisp....It only had 12,000 miles on NEW (rebuilt!!!) GM tranny....The tranny shop said it was bad when GM built it,He said their relays where junk also,He said they tested OK but bet they would fail...I know him and trust him so it is what it is...ETC.The guy I got it from had the Tranny put in at Chevy garage....over $2,000 and never did work right,they tried to fix it,even replaced it once more...different problems.That's why he got pissed and got rid of it.He has a 83 1/2 ton with 6.2 he drives now.He has been in this motor before but I don't know if he ever put a timing chain in it. And for the smoking it's just at start-up so I think the injectors are leaking fuel off etc. My brother has a Duramax and he started mine to pull it in the shop and said the injectors needed changed...My first diesel.............Could the head gasket cause blowby on the PCV hose??? The truck has power,don't smoke out the pipe..
I know on a gas motor a head gasket can do this...

Thanks Tom K.

[moondoggie]

Good Day!

If you got a 4L80-E that's been nothing but trouble, I don't think I'd bother rebuilding it, I'd get a different one. It's just possible there's something undetectable wrong with the case or such.

The 4L80-E is one of the toughest trannies ever built. MANY of us have 1/4 million miles on these with no problems whatsoever. This includes LOTS of folks that have spent a significant percentage of their miles towing trailers that are often real heavy. In other words, I find your experience to be unusual, way off the norm.

Good Luck & Blessings!

[keplinger78]

Good Day!

If you got a 4L80-E that's been nothing but trouble, I don't think I'd bother rebuilding it, I'd get a different one. It's just possible there's something undetectable wrong with the case or such.

The 4L80-E is one of the toughest trannies ever built. MANY of us have 1/4 million miles on these with no problems whatsoever. This includes LOTS of folks that have spent a significant percentage of their miles towing trailers that are often real heavy. In other words, I find your experience to be unusual, way off the norm.

Good Luck & Blessings!

Well just to make sure we are clear as mud,This is the third tranny that has been in the truck...1st one went 260,000 No overdrive,slipping in all gears,just worn out. 2nd one NEW GM (rebuilt) installed at GM garage work till 270,000 then had problems...(tell couldn't fix it or find out why it was messing up) so they replaced it with another NEW GM (rebuilt) that lasted another 10 miles before craping out...GM wouldn't stand by the 12 mile warr.because it had been 20k since he paid for the new tranny....but only 10 on the new one...So then I got it and took it to the Tranny shop that has been repairing trannys for 50 years..Father,Son,Grandson.It has been checked out and all they could find is a cracked servo for overdrive...so that would let the fuild not hold the clutches ingaged,slip and burn them up over time.As for reverse...well I has a steel utlitybed that is over 1,200 lbs empty,the guy said it weighed over 8,000 loaded with tools and such..He was a big truck mechanic.Reverse is not so great in these for that much weight.Try backing a regular truck with a car and trailer behind it up hill in high range..That's what happened it just smoked the discs...So I know what your saying but I have to trust them to FIX it...Not just put another New one in....I wish I could have got the 1st factory tranny that one would have been the one to get fixed...it had over 250k and still worked better than the NEW GM ones the guy said I got the truck from...LOL

Later Tom K.