EcoBrick Bob

Today, My A/C wouldn't turn on. Never got any messages anywhere on dash, but when I plugged in my DashHawk, I got this code. Called Onstar and they showed from their diagnostics that I had a coolant system issue. My Dash Temp gauge remained at 100deg though my DashHawk showed ECT temps of 165-171, and my dash oil temp was around 180-190. I have a 160 deg. Lighenfelter Thermostat installed, for around 900 miles, with no previous issues. Outside temp when we started was in the 70's. 630 miles later, where ambient temps on car thermometer came close to 100... and no A/C, I am one tired puppy!!!

So, tonite at the motel, decided we would attempt to fix. First cleared the codes and then disconnected the battery for about 15 minutes. Checked coolant tank and added nearly a quart of water. ( car will never see temps below 20 deg). Lastly, we moved the ground strap under the catch can bracket to above it and tightened it down securely. Upon connecting the battery and tightening both the positive and negative nuts securely, THE A/C started working!!!

Just wish I knew what the actual fix was. When I burped the coolant tank while adding the water, I did not get any bubbles, but I suppose it could have been the cause, if it was lower than normal. When I changed the T-stat, I didn't lose more than a few drops of coolant, so if it was low, it was either low from the factory, or it had gone out the overflow.

I just hope it doesn't happen again. 8 1/2 hrs without A/C in I-75 traffic (horrible today) was a real treat!

Opinions? Suggestions? Answers???

T/A KID

Same thing happen to my car, very apparent on longer trips 1.5 or longer. Delete that code and there is one more as well and it will fix the problem.

Yep the gauge will drop out and the ac won't kick on and the fans will stay on high

tblu92

Often when changing thermostats to a lower opening --on a cold day you will get codes for the coolant temps being too cold---So you have to simply delete or disable those low coolant codes in your tune---same was true on all LS1's LS2's and so forth---
I had to on my LT1 with a 160

6Speeder

Yep, on cold days sometimes the car doesn't get up to normal operating temp as quickly as the ECM expects and on the C7 (different than the C6 or C5) it will shut off the A/C, disables rev matching, and the coolant temp gauge will read zero. You have to turn off that code in the tune.

Could be worse, my Lingenfelter 160* thermostat just failed, staying open all the time. Had to put the stock one back in.

EcoBrick Bob

I'm wondering if mine failed also. Today I saw 155 deg temps on my DashHawk when it was nearly 80 deg out. Had worked great for 900 mi over 2 months. Not ready to tune the Vette yet. Have tunes in my other 3 cars, and when I had issues with my Flex engine (my fault) Ford could tell I had flashed the ECM over 100 times (TRUE!) and that the last flash occurred about 15 mi before I brought it in with a miss. $8,400... lesson! Basically hydrolocked the engine by spraying alcohol instead of methanol, and lugging the engine. Ringland fractures required a new long block. Waited a year to re-tune. Now has 55K on new engine and all is well! Quit spraying for good! Did turn several 12.9's though...

Live and learn!

At least today, I got a check engine light with the same P0128 code. That meant I could clear the code, which I did, and I didn't have it show up again the remainder of the day. Yesterday this failure occurred without any check engine light, and even when I cleared the codes the P0128 error from both current and history, it immediately came back, even though the outside temp was at 90+.

Will put the original back in, and perhaps order the 170. My gas mileage also suffered, as when this code happens, it won't go into V4. Best short term gas mileage was 29.4mpg... This is an A8 Z51 with about 2500 mi, of which over 1200 have been put on in last 2 days. My C5 Stick got better mileage on long trips. Not complaining as my other cars get around 20 mpg.

FYREANT

weird.. this happens to you right after I have overheating problems recently. Topping off my fluid seems to have fixed it. hope the same for you..

tblu92

Sounds like your blown motor was caused by spraying the alcohol even though you still somewhat blame the tuning---Tuning only allowed them to know when the last reflash was--Sure they are going to blame the last thing you did on your car as the cause of the failure---But the truth is that the tuning was NOT the cause---I can bet you never told them you were doing meth injection ! I would think that would be an automatic warranty rejection for any manufacturer--

EcoBrick Bob

I am convinced my Lingenfelder 160 deg thermostat is not working properly. Again today, the car timed out because it never got hot enough in the 30 or so minutes it was expected to by the ECM. However, once warmed up, I was able to clear the code and the car worked fine all day, even with the outside temps below 60 deg. So, I think the thermostat is never closed, which means it's defective, as it should stay closed till 160 deg, which would have been enough heat to keep the ECM from going into limp mode. At one point yesterday, my ECT Temps were in the 150's with this thermostat, and that was when it was over 80 deg outside.

Will switch back to original tomorrow when I get to our summer home. Then I will contact Lingenfelder and see if they can test it when I send it back.

FYREANT

Why not test it yourself? Boil some water on the stove and throw the TStat in the pot with a thermometer and see what happens..

6Speeder

That's exactly what mine did. 20 miles on the freeway at 70+ mph in 50 degree air the engine temp stayed at 140-150. Put me in limp mode.

T/A KID

Nothing wrong with the thermostat....gotta disable the codes.
If the car doesn't reach roughly 170 degrees in a short time (internal timer) it will go into limo mode.

6Speeder

No, if you can drive 20+ miles and the engine temp stays in the 140's like mine did, it's a bad thermostat. Failed open.

Now you CAN get the code with a good thermostat, happened to me once on my C6 Z, temp didn't come up as fast as the ECM expected. We disabled the code, no more problem.

ect

Had to replace my Lingenfelter 180 t-stat. Car would not warm up. Took it out and found the o-ring had split in two places. I think there sqare outside section o-ring can not find it's wayback into the sqare edged counter bore and being cut in two by the spring pressure. They sent another one no charge. I put a chamfer on the top edge of the c-bore in the t-stat housing. The sealing of the o-ring is to the next surface. We'll see if this works

EcoBrick Bob

Late yesterday and again this AM, when I had a cold start, I went to manual mode after a couple minutes of initial warming, and kept the engine in the 3000-4000 RPM range for a few minutes till the engine reached 160 deg+. Afterwards my engine varied between 160 & 165 deg and I never had a code even with outside temps in the 50's! It makes sense to me that the engine isn't heating up correctly because the Lingenfelder 160 T-stat has failed, either with the seal issue, or just plain stays open all the time. If it is closed and working, the car should heat to 160 or higher just as fast as the stock T-stat. I will call Lingenfelder tomorrow for suggestions. I would just as soon go to a 170 deg T-stat, considering the temps I was getting when I believe it was working, but perhaps the seal was an issue from the start. My goal is to get operating temps around 180 range, so if I do WOT runs at the strip, it never exceeds 200.

Thanks everyone for your comments. Any other ideas are always appreciated!

ect

Just ordered my third 180 t-stat.

6Speeder

Why your third? Three cars or two previous failures?

EcoBrick Bob

If I put A8 in manual mode and run 3500 RPM for about 3 miles, I never get the code. However, I still see temps on my DashHawk in the 150's.

I am convinced it is the T-stat as any T-stat should remain closed to the temp it is rated for, so engine should heat up to 160 just as quickly with all T-stats rated for 160 or over.

I now have a Lingenfelder 170 T-stat and my Halltech Intake, which I plan to install tomorrow. Will test the 160 T-stat then. Didn't want to take out coolant until I had a replacement. Will report back when I both test the 160 in a pan of water, and drive the car with the 170. I am guessing that when I pull out the 160, that it will prove defective just by looking at it..

I now have the same code coming up on my Ford Flex. One bank shows that the catalytic converter is not heating up quickly enough. However, my Flex heats up just fine and is running in the 180's with a 170 deg. T-stat. I think the problem in this instance is a bad O2 sensor. Vehicle has high flow cats that have not coded in the 30,000 mi they have been installed until now. Fortunately my A/C and everything else works fine, just a stupid solid check engine light. Even if I clear the code when the car is hot, it returns in about 15 minutes.

Any ideas on this issue???

Thanks!

ect

I think my second one is starting to fail. On 70 deg. day water temp (digital) is stabilizing under 180 , between 175 and 177 . When first installed it would go to 180+ and then never lower.

6Speeder

That's bad. Lingenfelter just replaced my bad 160 degree thermostat, thank you Lingenfelter.

I might just wait a while to put the new one in, see if others are having more problems.

EcoBrick Bob

When I called them and explained my situation, they wouldn't replace it without getting it back and testing it. Today's the day I pull it out! Maybe it is just a cut gasket????