There should always be some kind of code thrown or pending if the converter clutch function is inoperable. Does your trans still use a functioning input speed sensor?
CK5
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Need some help with 4l80e
- Thread starter Abusfullofnuns
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Both speed sensors on the tranny are operational. I had a broken wire on the upper one and immediately had the speed sensor code. There isn't anything from the mechanical speedo back to the transmission, but I think that it has been programmed for the gearing.
Only other code was a lean condition popped once during a long idle. I had a oil leak at the cooler fitting on the block and coated the underside with oil. The PO stopped the drip with some sort of epoxy and I accidentally removed it with high pressure brake cleaner. Ive got a block off plate on there now. Not sure how it would be related but that was the only other code I've had in 1600 miles.
If you can find a shop with a breakout box that can control this trans outside of the factory computer then you can see if it is trans or computer related and narrow down your search. You can probably make your own breakout box without too much trouble, I have seen these on the internet when folks wire the 4L80E for manually switched use.
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Thanks again. I'll do some looking around for info. There are a couple of trans shops on this side of Nashville that I'll drop in to visit for a chat.
I did have two ten mile drives on the interstate last night that did not trip the code. I'm sure it will today though.
What stall speed converter did you end up going with? My 80e is from a 97 suburban, pretty sure mine is the low stall speed and I'm thinking about swapping it out for something with alittle more stall.
did you find the problem and/or solution?
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I ended up going with the lower stall, and I think the stock one was higher. There was a more noticeable engagement prior to the swap and it's either the t/c is crappier or the effect of the stall change. The oem one may have been a better converter, it was definitely heavier. It didn't end up being my problem, and I wish I had the stock one back. It was low mileage and I learned my lesson in jumping the gun on diagnosing an issue in a drivetrain that was still new to me.
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Sort of....maybe. I ended up buying a hp tuner set up and digging into the trans diagnostics a little more. i realized that my crappy temp gauge was not right, the trans was functioning correctly, and the code was likely being triggered by a misfire. I changed the plugs and have only had the code reappear once over the last 2000 miles of daily driving. P0894 again. It happened on a stretch of interstate that has me cruising at 80mph and off the throttle going down hill for a 1/2 mile or so. I reset it and haven't seen it again. I haven't figured out why it fouled the plugs, but it's never been on a dyno to tune. The wideband seems to be really good for a naturally aspirated engine. It runs a bit rich during the transition of coming off throttle. That's the only time I've ever see it get over 14.7. Depending on tps, it's always between 13.6 and 14.5.
I have ignored the gauge that I think is faulty and monitored through the torque pro app. The temp behaves pretty good and runs at 175-180 after it gets to temp, but I've seen it increase temp slowly to 200-205 degrees a couple of times. It happens after interstate speed at 180 degrees and then slowing down to exit will add a few degrees. Consistently doing this will add temp each time, as does getting off into stop and go traffic. I haven't had a need to take it past the 200 degree mark in my travels, so I don't know if it will continue to heat up. This has all been with really high humidity and high ambient temps. I'm interested to see the effects of a cooler temp.
I really need to hook the tuner back up and start doing some more data logging. I have lots to learn with the hp tuner software.
My experience with 4L80-E is that the gauge in the cluster is designed with some lag and you'll see temp changes faster on a scanner. Is the engine temp also increasing? It could be a fan/clutch issue letting the trans warm up. With an HP tuners setup, you should be able to scan lots of stuff. Make sure TPS, MAF, MAP, CLT, input speed and output speed are all looking normal. You should also be able to see when the PCM is commanding lockup. You can log everything while you drive, then look at it later. If lockup is commanded and not happening, there's either a leak in the tranny or a bad solenoid/wiring. If the lock command comes on and off at weird times, that's a good sign one of your sensor inputs is wacky.
What converter did you end up going with?
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Dayco
I think they are sold under Trans star or Trans state or something too. They have a facility in TN and had one in stock. I wish I would have gone with an upgraded unit just as a piece of mind.
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Oh yeah, for sure. I was logging quite a bit while still troubleshooting the code, but haven't followed up with the small temp increases. It takes a specific drive and traffic scenario to make it happen. i set up a profile to log all of the trans functions, but can't seem to find it anymore. I'll have to go relearn how to add parameters again. I used it for some emissions reconfiguration adn then put it away. I kind of wish that I went for the one that can log without the laptop.
A stock 4L80E converter is a pretty strong piece, the bowl is furnace brazed, the clutch dampener and turbine hub and stator bearings are all quite large and strong and I'm sure your reman converter has had a new clutch bonded to it. I wouldn't worry about breaking it.
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I don't doubt it, and I don't plan to ever do any major power adders to the motor. I guess I was more doubting the quality of the reman converter than that of the durability. It just never felt the same after the swap.
I went to a local guy here in town that has the equipment for opening a torque converter and rebuilding it. Then I went to a company called Sonnax, and bought a billet piston and a billet stator that the guy who rebuilt my converter installed. I also had the guy who rebuilt my converter put in new clutch lining material. I had him leave the stall speed stock. Since my 4L80E has a small block in front of it, the stall speed is about 200 RPM higher than a big block. The whole thing cost me about $375, and the converter works like a champ.
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Thanks man, I’m really trying to decide if it’s worth swapping converters.
@Greg Ducato are the Hughes xtm converters pretty good? Is the stall difference between the vortec 80e and ls 80e noticeable?
Hughes builds a nice converter, the later 4L80E converters have higher stall speeds available but the early units have a better clutch piston/damper. I don't know if you could tell the difference between the two series if the stall speeds were both the same rating.
