Anyone with the I6 Headers please look.

XUVFISCH

XUVFISCH

Member
Joined
Mar 27, 2013
Posts
36
I installed my headers and now I'm getting a P0894 code. I get the code after driving it at highway speeds. 1st to 2nd gear it has a hard shift. After the voy cools down the shifts are back to normal until it heats up again. I had the trans rebuilt about 1 month ago with heavy duty parts. The trans was done 100% correct (friend of the family who rebuilds race trans) Trans fluid is clean red and full.

also on the way home today I got a P1133 code


Anyone with the new 4.2 headers, have you had any of these problems???!!!
 
Did you reset the pcm after you replaced the manifold? Its always a good idea after you replace any major parts
 
If you mean disconnecting the battery, yes it was disconnected for over a week when I installed the headers. With broken bolts and Kooks having to send me out an extension piece for the long wheelbase, it took over a week to finish.
 
I honestly don't think the headers have anything to do with the shifting issue, I want to speculate it's the trans itself, possibly something overlooked. Can you elaborate on what was replaced when it was rebuilt? I understand it was a family friend and I'm not doubting his/her expertise, but this is generally associated with accumulators or maybe even a leak elsewhere.....could be a bad boost valve?

Did this happen the day after you installed the headers and drove it for the first time? Were the trans and headers serviced at the same time?

Were any parts reused when the trans was rebuilt, this is important. Was the valve body serviced?

Sounds like a leak is being generated somewhere in the trans, could be something very simple and only requiring a pan drop. Hopefully it's not a bushing or seal requiring a teardown but start at the easiest areas first.

That being said, at higher throttle settings the trans uses higher pressure to work the shifts, could very well be the ECM thinking you have high throttle settings at part throttle but this would generally happen all the time.
 
Trans was rebuilt July 23 headers installed Aug 7 trans had overhaul kit, tc rebuilt, HD sun shell, sprags, pump kit Not sure what else was done to the valve body
I thought that the trans was running hot because of the headers, but I have a OBD2 and bought the torque Pro and found out that the trans temp was never higher then 227 degrees at 70mph and outside temp at 70 degrees. I seems that if I turn the key off and restart it after 30 min of driving, the shift from 1 to 2nd isn't as bad as if it was running for over 30 min. I've red a few posts about the P0894 code, and most of it is similar to what I have. Do you think it would be something that would need immediate attention or could it wait. I have a trip planned on Monday and don't have time for my trans guy to look at it.
 
XUVFISCH said:
I thought that the trans was running hot because of the headers, but I have a OBD2 and bought the torque Pro and found out that the trans temp was never higher then 227 degrees at 70mph and outside temp at 70 degrees.
Click to expand...

That's pretty hot unless your pulling a good grade with a trailer attached. Does the torque converter lock in OD, or 3rd at hwy speeds? This MUST happen.

How close are the cooler lines to the headers?

Providing you are just cruising along with just the Envoy at a steady 70 MPH cruise, TC locked, you should be nowhere near 227 deg.
 
how do I tell if the torque converter locks up?

The headers are about 4 or so inches from the cooler lines.

It's so damm hot under the hood after I drive it highway speeds, I cant believe something hasn't caught on :lipsrsealed: fire yet.

I'm gonna try and wrap the headers tomorrow with some DEI exhaust wrap and wrap the cooler lines with reflex a gold heat reflective tape and see if that helps.
 
how do I tell if the torque converter locks up?

Get going in 4th (D) and after it shifts into 4th, keep steady pressure on the gas pedal (don't let off) and you should see the tach drop another 200 RPM or so. When it does, if you depress the pedal further using light pressure, the tach will not jump up and rise very steadily. To test this, keep steady pressure on the gas and use your other foot and tap the brake, the TC should come out of lock and rise about 200 RPM.

The headers are about 4 or so inches from the cooler lines. That's fine.


I'm gonna try and wrap the headers tomorrow with some DEI exhaust wrap and wrap the cooler lines with reflex a gold heat reflective tape and see if that helps.


I wouldn't try that just yet, under hood temps generally are hot. When you wrap the exhaust you retain heat around the head and I don't know if that's a good thing with aluminum heads....others can chime in. I know headers can be wrapped but I'm basing this on small engines.

There are positive and negative effects from wrapping headers, mostly positive but research first before you do.
 
I'll try the lock up thing tomorrow,

I was gonna try and wrap the lower half of the headers, where they come together. The trans dipstick tube is about 1" from the header. you can see it in the pic
 

Attachments

  • 20130801_132142.jpg
    20130801_132142.jpg
    93.8 KB · Views: 27
Not having the factory heat shield can surely change things I suppose, especially radiant heat. If it were mine I would probably wrap some of it but prob not right at the head. There are aftermarket heat shields in the form of tubes with reflective exterior coatings, like used in AC lines. I'm sure you could possibly shield the trans stick due to the close proximity of the headers.

Sweet looking headers, wish I had a set but out of the budget right now.
 
XUVFISCH said:
I installed my headers and now I'm getting a P0894 code. I get the code after driving it at highway speeds.
Click to expand...

You need to diagnose the TCC solenoid with a scan tool. It should lock up at highway speeds but it doesn't seem to be. Check it's wiring for shorts.
 
CaptainXL said:
You need to diagnose the TCC solenoid with a scan tool. It should lock up at highway speeds but it doesn't seem to be. Check it's wiring for shorts.
Click to expand...


So how would I go about it with the scan tool? Can you run me thru it?

would excessive heat in the trans mess up the TCC solenoid?
 
XUVFISCH said:
So how would I go about it with the scan tool? Can you run me thru it?

would excessive heat in the trans mess up the TCC solenoid?
Click to expand...

You call 225 excessive heat? lol. Um in a nutshell....no it wouldn't. The older THM400 trans would could get as high as 275 F without a cooler. So it's not a problem. Have a competent shop that has a bidirectional scantool perform the diagnosis.

I don't think any of the handheld cheaper scan tools will properly check it. It needs to be commanded on and off.

The PCM monitors engine RPM on a constant basis. When PCM commands the TCC to ON but the engine RPM never changes then the code will be thrown. In other words the PCM is basically saying to you that something in the trans is slipping. At those speeds it could only be the TCC.
 
CaptainXL said:
You call 225 excessive heat? lol. Um in a nutshell....no it wouldn't.
Click to expand...

I agree...:smile::lipsrsealed: Something tells me that just straight, solo cruising the fluid shouldn't be that hot. If the TCC is not engaging it will surely heat up the fluid.
 
Sorry, I didn't mean excessive, but what I found on the forum it should be around 200 without towing. Would a bad TCC cause higher heat in the fluid?

Can I try the taping on the brakes at highway speed, to see what the RPMS do. Will that tell me if the TCC is bad?
 
XUVFISCH said:
Would a bad TCC cause higher heat in the fluid?

Can I try the taping on the brakes at highway speed, to see what the RPMS do. Will that tell me if the TCC is bad?
Click to expand...

Absolutely. Without TCC engagement the TC heats the fluid, when locked it's like a clutch on a car, no slippage.

After the TC engages, tap the brakes without lifting of on the accel pedal. When you lift your foot off the gas the TCC disengages.

Not knowing what was replaced, it's always good practice to replace the torque converter when rebuilding a trans.
 
XUVFISCH said:
Sorry, I didn't mean excessive, but what I found on the forum it should be around 200 without towing. Would a bad TCC cause higher heat in the fluid?

Can I try the taping on the brakes at highway speed, to see what the RPMS do. Will that tell me if the TCC is bad?
Click to expand...

Ah I see. Just exaggerating.
200 sounds about right with the truck in 3rd or 4th gear on the highway without a TCC lockup. 175-185 is about the temp it should be at 70F at 70mph. I have seen this in both 4l60e and 4l80e trucks with all different engine sizes.

I could hop in your truck right now and take a test drive to see if the TCC is performing the way it should. Your buddy that rebuilt the trans should know this as well. And I am not what you would call a competent tranny rebuilder. So am I missing something here or is this just a matter of getting out of the house and taking it to be looked at?
 
Thanks gmcman and CaptiainXL. I get out tomorrow and give it a drive, wife's been calling me to bed for the last hour now. :rotfl:


(Torque converter was rebuilt with the trans)
 
OK, took it out for a drive this morning. when I first went down the road, I can tell when the RPM's went down and when I hit the brake they went back up. it worked for about 2 miles of driving around 45mph. Then when I got to a higher speed road at 60mph, it wouldn't lock up. I taped the brake and nothing happened. on the way back home it would lock up again around 40-45 mph. Then I got on it really hard to get back up to around 45mph, it didn't lock up again. My conclusion is that it sometimes locks up and sometimes doesn't. when I started the trans temp was 80 and when I got home it was 170 for about a 5 mile drive.

How hard/ long would it take would it be to replace the TCC? I'm leaving on vacation (Mackinaw) on Tuesday and don't know how busy my Trans guy will be Monday.

Last Question: Would it be OK to drive like this for the next 600 miles or so?


And Thanks for all your help!!! :thumbsup:
 
You should be fine if you keep it in 3rd. Just wasting gas thats all. Your tranny guy should have replaced it though when rebuilding it. I would take it back to him. You might need a new solenoid or torque converter.
 
Something to keep in mind is the TC won't lock unless there's a load on it. If you get up to speed, I would try 65-70, and have steady pressure on the gas then tap the brake and look for the unlock. I know mine wouldn't lock until the trans came up to temp so you may need to drive it a few more miles.

You can tell by rocking the gas pedal and watch the RPM, if it jumps up every time it's unlocked, if it stays put then it's locked. Just don't let it coast, keep trying to accelerate lightly but don't let off completely.

You also have to be at a certain speed to see the lockup unless you remove the PWM control. With the 4:10 gears mine wouldn't noticeably lock until about 55 MPH in 4th, yours may be higher.
 
As i understand it you are reading the tranny temp with the tourqe app, right?.

Did you use the right PID?, there are three i think and one of them is giving you a much higher temp reading than the other two.

You also have a Pid that is called TCC Slip speed, this does not work with all phones, but i got it to work on my Sony Xperia Z.
This will show you how much slippage there is in the TCC, its hardly never at 0 but it should be close to zero like 5-20 if the
lockup is working OK.


Edit:

There are 4 different pids.

"transmission fluid temp (GM method 1 and 2)"

And there is "Transmission temp method 1 and 2" these would give you a much higher temp reading for some reason.


I have just returned from a 1200 mile vacation journey with my 4500lb caravan and i have never got higer temp readings than 90C 194F .

OK i got a external cooler but uphill at low speed it doesent do much anyway, but it cools down faster when the speed is increasing again after the hill.
 
gmcman said:
Something to keep in mind is the TC won't lock unless there's a load on it. If you get up to speed, I would try 65-70, and have steady pressure on the gas then tap the brake and look for the unlock. I know mine wouldn't lock until the trans came up to temp so you may need to drive it a few more miles.

You can tell by rocking the gas pedal and watch the RPM, if it jumps up every time it's unlocked, if it stays put then it's locked. Just don't let it coast, keep trying to accelerate lightly but don't let off completely.

You also have to be at a certain speed to see the lockup unless you remove the PWM control. With the 4:10 gears mine wouldn't noticeably lock until about 55 MPH in 4th, yours may be higher.
Click to expand...


I took it for a 45 min highway drive trans temps would get to 222 at highest at 75mph. 70 outside temp. Could not get the TC to lock at all at those speeds at all. I could at lower speeds like 50 after it cooled down a bit.
 
Harpo said:
As i understand it you are reading the tranny temp with the tourqe app, right?.

Did you use the right PID?, there are three i think and one of them is giving you a much higher temp reading than the other two.

You also have a Pid that is called TCC Slip speed, this does not work with all phones, but i got it to work on my Sony Xperia Z.
This will show you how much slippage there is in the TCC, its hardly never at 0 but it should be close to zero like 5-20 if the
lockup is working OK.


Edit:

There are 4 different pids.

"transmission fluid temp (GM method 1 and 2)"

And there is "Transmission temp method 1 and 2" these would give you a much higher temp reading for some reason.


I have just returned from a 1200 mile vacation journey with my 4500lb caravan and i have never got higer temp readings than 90C 194F .

OK i got a external cooler but uphill at low speed it doesent do much anyway, but it cools down faster when the speed is increasing again after the hill.
Click to expand...


I followed the direction on a different post about Torque PRO. I am using GM method 1. (1 and 2 give same temp)

I also have the TCC slip speed. it gives it in RPM's. it stays around 500 RPM range and fluctuates.

Taking the Voy back to the trans shop in the morning to have him look at, hopefully he can fix it in 5 hours. I'm going to the Kid Rock :celebrate: concert tomorrow night and off camping Tuesday early :sleepy: morning.
 
500rpm:eek:, thats what i get when going upphill with the caravan, 5-650 rpm in third gear when the lockup disengages.
 
Harpo said:
500rpm:eek:, thats what i get when going upphill with the caravan, 5-650 rpm in third gear when the lockup disengages.
Click to expand...


I took a better look at it today and it was more like around 200 rpm when driving around 50mph



I took it back to the trans guy, he didn't have time today to check it out, but said it would be fine for me to drive it on vacation.

I'll update next week when I get it back into him what the problem was.
 
Little update. We made it to Mackinaw. Trans temps were highest 240 uphill and 228 flat road. 3rd gear. Did have another code come up after we stopped for gas. P0741. And my cruise control stopped working when we left in the morning.
 

Attachments

  • 20130820_162415.jpg
    20130820_162415.jpg
    99.1 KB · Views: 16
You've got an issue with your torque converter clutch bud, both the codes you mentioned are directly related to it. And it doesnt sound like it's locking up correctly either. I would take it back to your builder and see if he replaced the converter, usually when a trans blows you want to replace the converter otherwise you'll end up pulling it out again and doing it then (metal shavings in lines = bad). Replace the radiator as well if it blew, you'll have metal in the cooler.

P0741- TCC stuck off
P0894- Trans component slipping

P1133 - B1S1 HO2S insufficient switching. Who tuned it after you put your header on? You need to have it tuned...Id highly recommend getting your TCC stuff fixed first though.
 
Thanks for the info on the torque converter. Im taking it back when i get home from vacation. Im gonna get it tuned but needed to get a week first that i didn't need the envoy. But the trans stuff came . So getting that done first
 
In the morning drive it about 5 miles come back and let it idle for about 15 minutes and see where the trans temps are let us know
 
Last post from crappy phone... last part should have read that I'm curious as to the accuracy of your temp signal or the app you're using. Just drive it 5 miles easy with no towing and let it idle.

240 is hot bud...ATF begins to oxidize at high temps...at 250 the rubber seals begin to harden. Every 20 deg above 175, fluid life it cut in half. Momentarily at 240 is probably ok, sustained is not good.
 
Ok. Drove it 5 miles. Sat idle 15 min. Temp was 167. outside temp was 78.
Im still thinking its the headers heating up the trans. But I'll have to see what my trans guy says before I can see for sure. I was hoping someone with the headers would chime in and tell me what their trans temps are at.
 
My trans temp stays around 10F below ECT. obviously your trans fluid is going through your radiator and will be close to ECT.
 
jimmyjam said:
My trans temp stays around 10F below ECT. obviously your trans fluid is going through your radiator and will be close to ECT.
Click to expand...

What's your ECT temp at? and what is that?
 
engine coolant temp. mine stays between 190-200
 
I picked up the envoy from the trans shop yesterday, he said the changed the wiring harness and solenoid. On the way home about 25 miles, it threw the p0894 code again and the TC did not lock up again. I turned around and took it back to him, he gonna try and change the TC next.

I'll let you guys know in a couple days what happens.
 
OK, I had the Torque Converter replaced, It now locks up at highway speed. My trans temp get to 180 on the highway doing 70mph at 60 degrees air temp. When I drive in heavier traffic around 45mph with traffic lights, (not stop and go) it goes to 205 degrees.

Does this sound like the temps I should be getting. I never had Torque Pro, to see my temps before I installed the headers.
 
You must log in or register to reply here.

Forum Statistics

Threads
24,309
Posts
649,120
Members
20,842
Latest member
natehaus

Members Online

No members online now.
Total: 3,043 (members: 0, guests: 3,043)

Share This Page

Share This Page
Top Bottom
Back