2000 Chevy Venture P1811 Problem Again

[Beast of Busco]

It has been a LONG time since I posted, but need some advice for my 2000 Chevy Venture van. When I got the van from my grandmother in September 2009 (about 90K miles), I had the PCM solenoid replaced due to the P1811 trouble code. It ran great until we were on our 4500 mile vacation last August when it demonstrated the same issue on the way home (whine, shifting hard). We ran it REAL hard during vacation (even taking it up PIKES PEAK).

It did the same thing once when we got home, but I put off doing anything about it as I really didn't want to spend the money after a big trip. However, it worked perfect all winter and spring, shifting just fine, until the weather got humid and the problem returned.

I took it back to the shop and they said it had the P1811 code again. But it still only does it when it is warm outside.

Thinking I really didn't want to replace the solenoid again, I did additional research on the internet. I read where some people had success with Seafoam transtune, so I purchased it and added a half a bottle to the transmission fluid. I have ran it less than 100 miles with no issues, but it hasn't been hot either. I also checked into adding an additional transmission cooler (it has the one built in to the radiator), as my thinking was the problem could be related to heat as well. I read where the solenoid could get varnish build up and am hoping the Transtune helps clean it up.

It has 118K miles currently, and I believe they changed the fluid when the solenoid was replaced at 90K (It was also done at about 75K).

I am thinking about running the Transtune for a little while and then dropping the pan and changing the filter and fluid.

Any thoughts?

 

[eljefino]

The pressure control solenoids on these things aren't great. I'm not aware of Seafoam being supposed to be in transmissions.

Of all your options, the big cooler seems like the best. Plumb it so fluid goes through it *after* the radiator, on the way back to the trans. If the solenoid is overheating, the fluid doesn't matter much, and clean fluid won't help it work much better. (I doubt it's sludged up in there.) Cool fluid might help you gimp it along.

 

[WishIhadatruck]

I had the same issue with my '01 Grand Prix with the 4T65E trans. I've had an external cooler plumbed in with the rad. cooler since 60k miles. Around 100k (I don't remember when) I had the same problem one spring on a hot day after running some city errands. I typically only run on back roads and the highway. That summer I noticed issues everytime my routine changed and I ran some errands after work on a hot day. Pump whine and shifts that banged, hard. Fall came and with cooler weather the problem never returned. That winter I put in a shift kit based on others success (not 100%). I probably had 120k miles since I did the kit when I did my typically 30k mile trans fluid pan drop which would have been at 120k. I have not had a problem since. That was the winter of '09-'10 and I now have 155k miles on it with no reocurrence of the issue. Ocassionally on really hot days I'll feel the shifts firm up but it is such a mild change that most wouldn't even notice, nothing like the banging of the past. For as little as it cost ($30?) it was definitely worth it. It is worth trying even if it doesn't work considering the alternative.

I just looked it up. $39.99 plus shipping from ZZPerformance on their website. Many others have used a kit from Transgo I believe.

Edit: I'll add that my dad had the same issue on his 2000 GP and added an external cooler hoping it would help. It did not. I already had a cooler and it wasn't helping. I've had my car since new and have always done 30k pan drops and I even did a UOA at 90k which looked good. Based on that I'd say that keeping clean fluid in there won't help either. I used M1 Dex III until 90k miles and have used Dex VI since.

 

[jkhawaii]

with out looking it up I do not know what p1811 is but it sounds familiar. check the wire harrness from the trans and around the ac lines and accumulator, the harrness is known to rub and short out, mostly on the ac accumulator

 

[Beast of Busco]

The frustrating thing is that the solenoid only lasted about 1 year and 15k miles before it acted up again. How hard is the shift kit install? If I am going to drop the pan it might be something worth doing.

 

[sciphi]

The shift kit is easy to install. If you can drop the pan and replace the filter, you can install the shift kit.

My Buick's 4T65 was gimped along on a shift kit of some sort (first a ZZP clone, then a TransGo) for 40k miles before I had the PCS replaced. Now with a TransGo shift kit and a new PCS, the shifts aren't harsh at all.

Of the two shift kits mentioned so far, I'd recommend the TransGo. It has replacement springs to help out the PCS, instead of just the spacers in the ZZP kit. I've used both, and like the TransGo better for smoother shifting, and being a more comprehensive fix for the problem.

Recommendations: Transmission cooler and shift kit. Those will help your 4T65 shift as well as it can at this point.

 

[caravanmike]

Originally Posted By: Beast of Busco
However, it worked perfect all winter and spring, shifting just fine, until the weather got humid and the problem returned.



vacation with kids and gear is very tough on a minivan platform. if it only does it when it is hot out i would go for the big cooler and a fluid change!

 

[Beast of Busco]

Here is an update...

The sea foam trans tune did NOT help, so I installed a large aux transmission cooler. That really didn't help either, so I took it in for diagnostics and they found the p1811 code and replaced the solenoid.

Unfortunately I am now on my THIRD solenoid since August and the problem STILL exists! The shop says they have a rash of bad parts, but that doesn't seem to make sense. Going to call them again tomorrow....but does anyone have any suggestions besides trading it in...which has crossed my mind!

 

[sciphi]

Did you ever install the TransGo shift kit? That WILL mask the problem well enough to get another few years out of the transmission. Even if the solenoid goes south, the shift kit will have enough mechanical force to work in 95% of your driving.

Also, my old Buick's 4T65 really did shift better on Valvoline Maxlife ATF. Since the pan needs to be dropped to install the kit into the accumulator pistons, why not fill up with Maxlife?

Between those two, your P1811 should take a well-deserved hike and not come back for a long while.

 

[Beast of Busco]

No I didn't do the shift kit yet. I thought I would try the cooler and when that didn't work I went with the solenoid replacement at the transmission shop. I am thinking it is probably worth the $70 to try it now!

 

[gw105]

Check out this thread, tranny flush with valvoline maxlife atf and lubegard red made the tranny in my 2003 pontiac montana shift like new!

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2375691