MIGHTYM0USE

ANY aftermarket thermostsat where the rubber is molded over the rim instead of crimped down into it;
-I have tested Lingenfelter AND the 'Summit' brand personally; Since they all came to market at same time and same visually there is plenty of reason to believe they are all same original manufacturer.




-you will notice your coolant does not come up to temp, or comes up very slowly
-your fans will cut on high
-your digital and or analog coolant temp will drop to zero
-you will get SES light and code (P0128, Coolant below regulating temperature)

The seal cracks/tears/gets blown off and down into the water neck.



My stock thermostat was available, so I pressed the center (easy) out of both and put the 160 bulb into the oem disc. You will need a pair of pliers or side cutters to ease the lip in to hold the new bulb snug. Once installed the water and bulb pressure will not allow it to come apart.




Back to working normally; 165 on the highway

If you do not change your thermostat setting in the tune you may still get the code because the car is still looking for 194* minimum operating.. Look in the tune for this:



I had no trouble with this changed to 175*

The ONLY direct drop in seems to be this exact Mishimoto, however from one of the threads above there is a customer who got an older Mishimoto stat designed like these others and of course it also failed (last in the following links). So ask them for a picture or something before buying.

https://www.corvetteforum.com/forums...post1593121984


Relevant threads:

https://www.corvetteforum.com/forums...t-install.html
https://www.corvetteforum.com/forums...ermostats.html
https://www.corvetteforum.com/forums...hermostat.html
https://www.corvetteforum.com/forums...hermostat.html
https://www.corvetteforum.com/forums...the-ls3-2.html
https://www.corvetteforum.com/forums...good-idea.html

This does not mean these stats are a waste of time to purchase, still hundreds less than the next option, but PLEASE don't bother to install it as-is. Do the bulb swap (or find that Mishimoto above) and be done with it.

EcoBrick Bob

Nice job!

I found that when the cut rubber issue happened on my Lingenfelder 160 deg. T-stat, the the A/C also quit... which was really hostile as I was driving back to IA from FL in high 90 deg heat!. I immediately ordered a 170 deg T-stat from them, just before they took them off the market, as I didn't realize it was the gasket that had failed at the time.

When I replaced, I also noticed that the spring was pinching the rubber seal on the new 170, due to a burr on the spring end where it was snipped off when mfg.... I filed this off and rounded the spring head so it was impossible for it to pinch the rubber seal. Vehicle has been fine now for 2+ months of stop and go driving.

If I have the seal fail again, your mod is definitely the way to go. Would do it now, but want to keep original stock in case of warranty issues, as I understand GM doesn't like us to replace the stock T-stat with lower temp ones.(Possible excuse to void warranty on engine.) Need to order a second stock one to modify.

BJ67

Mighty Mouse, when you drilled holes in the stock stat, that didn't lower your opening temp? what did or didn't it do. Is there any other way to mod the stock stat? instead of drilling holes or swapping out the center temp sensing pieces?

MIGHTYM0USE

if you drill enough or big enough holes it will let water move around and slow the warm up process. I drilled too many and on colder days or on all highway the car would not reach minimum operating temp, but the standing problem is that drilling the holes doesn't change when the stat opens, and slowing the warm up process is not really all that useful if the end result is still the same.

but it was free to try!

Wormwood

I've had some success heating some of the coils on the spring, reducing the pressure applied to the Tstat & lowering the temps. ~10°-15° . Of course nothing will work properly without adjusting the calibration on the ECM, so changing the Tstat in relation to warranty is nothing compared to changing the temp. calibrations within the ECM.

By heating a single coil at a time, I'm removing that part of the springs ability to return to its original shape, however, since this reduces the overall length of the spring as well, it limits the amount adjustment I can do. I need to find some different springs altogether.

Wormwood

Additionally, modifying the spring is probably why my Jet Tstat hadn't failed. Since there's less pressure against that rubber & the housing, it's not pinching it as hard.

BJ67

I have a 180 lingenfelter stat, its been in about 600 miles. Seems to be warming up slower now. I am watching it. How would I recalibrate the ecm, I do have a diablosport tuner but have not installed the tune yet

EcoBrick Bob

I decided to do your stock C7 Thermostat Mod. Used my 160 Deg Lingenfelder T-stat center with the stock holder, just as shown in the original post.

My main reason for doing this was to see how the Lingenfelder 170 deg T-stat with the rim mounted gasket was holding up. I am the person who filed down the spring before installation of the 170 a couple months ago, as I noticed the spring end was pinching the rim mounted gasket.

Unfortunately, when I pulled the Lingenfelder 170 T-stat, the rim gasket was also cut and twisted, so it was fortunate I removed it. I was suspicious that it had failed, as I did have one instance where the fans were running full blast, even though the engine temp was around 170.

SO... IT APPEARS THAT THERE IS NO WAY TO MAKE THE LIGENFELDER T-STAT's WORK. They definitely made the correct decision to quit selling them.

Before I merge/modded the original stock T-stat with the 160 deg center, I purchased a new stock one, which can only be purchased with the plastic elbow and spring cage that holds it. Total cost with shipping for part #12658723 was just over $50. Note this is for a 2015. The part # for a 14 is different and the price is less.

MIGHTYM0USE

yes unfortunately this may become a popular mod.

EcoBrick Bob

Shortly after my LF 170 deg install back in mid-June, I contacted Lingenfelder about what I thought I had found as the reason for the cut gasket. It was also just after they discontinued selling their low temp T-stats for the C7.

They offered to refund my money or replace with a revised one, when they came available. It has now been 10 weeks with no further information. I e-mailed them last night, so hopefully I'll know more next week.

For those who have a defective LF T-stat, doing this mod, using a newly purchased original T-stat would have an overall cost of around $80. That is close to what I paid for my 170 deg. T-stat for my Twin Turbo Flex, and much cheaper than the over $200. option that includes an aluminum housing.

Late Model Racecraft

We should have plenty on the shelves ready to ship. Please feel free to email sales@latemodelracecraft.com or just give us a call at the shop to place your order today.


Steven Fereday

Elite275

I've tried and spoke to someone twice and handled the credit card transaction over the phone to no avail. Nobody generally answers the phone and your VM box is full to try a 3rd time to get the transaction processed.

Newton06

I'm curious; mine is having similar problems with the LF T-stat installed.

How does a mechanical failure (i.e. a seal coming apart), cause the CTS to send the ECU into fail-safe mode?

EcoBrick Bob

When your car doesn't heat up quick enough or to a high enough temp, the ECM thinks that there is an issue with your cooling system that may be causing the engine to overheat ( low water etc) and it puts the vehicle into limp mode to protect the engine, turning on the fans and shutting off the A/C, in case the engine is actually overheating.

Since I did this mod using the 160 deg LF bulb and the original T-stat housing ring, and am again getting the code but no check engine light, I think the C7 ECM doesn't like temps that are under 170 after a certain period of time, like 10 minutes of driving or so. At least I have a 15' Z51 A8. 15' uses a different T-stat than 14', which is slightly lower temp from GM, so 15' runs slightly cooler anyway.

Newton06

I am going to pick it up from the dealer today and put the stock T-stat back in.

The symptoms to me sound electrical in nature.

Why would the analog & digital gauge read zero?

Why would the analog read zero and the digital read 164?

Why would they suddenly read the correct reading while driving.

Mine did not throw any CEL codes, but did disable the AC, and put the fans in high mode.

Very odd.

MIGHTYM0USE

if you do not change your thermostat setting in the tune you may still get the code because the car is still looking for 194* minimum operating.. look in the tune for this.

i had no trouble with this changed to 175


it is surely all caused by slow or not-reaching desired operating temp. why gm chose to trigger the things they did to get the drivers / dealers attention is something im sure we will never understand.

EcoBrick Bob

A while back, I read a post in the Z 06 C7 section that GM is monitoring for aftermarket lower temp T-stats ( perhaps just in Z06) and that if they find one installed, that it is a potential reason to void your warranty when expensive engine repairs are needed. While I have no proof of this happening, it could be a reason for the ECM programming that causes the limp mode situations. It was my impression that the reason for stock T-stat temps being as high as they are, is for emissions compliance, and possibly to help mileage numbers. But, I suppose it is possible that there is more wear in a cooler engine, which would be a GM long term consideration but I'm not an engineer so this is "Black Hole Science" to me.

My 170 deg. Lingenfelter T-stat never caused any issues until the rubber seal failed, and even then, when it went into limp mode, the next time out it didn't do it. At that point, I had received my second stock T-stat, so I decided to see if the 170 LF T-stat had failed and do the Mighty Mouse mod using the 160 deg. bulb if it had.

I did this mod without wanting to tune my ECM at this time. If it continues with the 170, I will go back to my stock T-stat.

MIGHTYM0USE

im sure gm reserves the right to void the warranty for anything aftermarket, and is more an excuse and deflect blame than some bona fide warning of impending danger

Newton06

Can anyone explain why either the thermostat gasket failing or the tune not being adjusted to reflect a lower temp T-stat would result in the temp gauges reading '0'?

Still not getting this...

Higgs Boson

car computer logic today is weird. better to just do than try and understand some of it unless it REALLY REALLY matters to you.

EcoBrick Bob

My DashHawk is reading the temps correctly while the gauge on the dash reads 0. My guess as to why the gauge on the dash is reading 0 is that GM programmed it to do that to alert the driver that there is something WRONG! You will note that the oil temp gauge on dash is still working when water temp gauge is not.