Tim’s Garage Episode 21: Saturn Sky Pontiac Solstice Thermostat 101 - Cooling your Kappa

[@Ikoleb]

Thanks ! Keep doing these videos. You can not imagine how helps to the people that leaves in countries where there is almost no information about solstice/sky/Opel. Gracias !

[@350tiger]

I am glad I can help !!

[@ronlebert4245]

Hi Tim, really good little demo on thermostats. I studied Motive Power Technology in College, one of the sessions covered cooling systems. We were required to diagnose a "controlled" cooling system deficiency. The problem was created by the instructor & we had to diagnose the problem. There was only one answer & it had to be the same result as the instructors induced problem. One of the setups was a sticking thermostat but that was only part of the answer, he wanted to know why it was sticking & you had to prove your conclusion using controlled testing. The testing required tables & graphs showing the difference between a new thermostat & the "test" thermostat. Your little demo would have gotten you a 100% as it was exactly what we needed to show in our results, boiling water & all. Bravo Tim!!! If I may add a bit more on coolant temps. As for the engines running around the 200*F + this is considered normal for our cars. The engines are designed to run these temps as it reduce hydrocarbons & delivers better fuel economy. On another point I find that many drivers try to run their engines @ lower RPM's 1500 to 2000 rpm. They say "That's where my other cars run on the highway so why not the 2.0L Turbo" ? Thinking that the lower RPM will reduce wear & deliver better mileage, but with our engine the opposite is true. It is better to run our engines from 2500 to 3000 RPM as it allows the engine to handle load requirements easier than the lower RPM. The lower RPM creates undue stress on the internal components. Also the higher engine speeds move the coolant through the cooling system quicker, the increased velocity of the coolant will remove heat from the engine helping it to run cooler. That's why your temps rise when you are sitting @ a light as the lower RPM reduces coolant flow through the system causing the temps to rise. Now I own a manual so it is easy to control engine speed, I would be interested to see the Automatics RPM's @ given speeds. & how it relates to coolant flow & temperature. Just my 2 cents worth. Again great job Tim. Ron

[@350tiger]

Ron that has to be one of the best comments I have gotten to date ! Thank you for sharing your insight. Took the car out again tonight in 86 degree heat and it seems there is still a small amount of water trapped and I may have worked it out. For me the tweaked OEM thermostat was likely sticking due to the spring walking out of its seat and causing the housing to shift ever so slightly and was resulting is a slight sticking on opening part way. This was causing 221-223 temps at the extreme as the stat restricted flow. The new thermostat with the slightly larger open area helps but the only remaining issue I suspect is an inefficient water pump at low RPM as the design is not the most positive displacement pump. My ACDelco replacement pump may improve things a bit but I am a ways from changing the water pump as it is still very good. At this point I now have a 197-210 degree swing and it is a lot better than the 198-217 degree swing I had. It is still early to say I am done with improvements but it initially seems a LOT better and certainly has a tighter temperature regulation. Thanks for your interest Ron! And for your comment!

[@ronlebert4245]

@@350tiger Tim your more than welcome! Perhaps you may be able to tell me why so many owners replace the water pump. What seems to be the issue with it as it is a very basic design other than the way it's driven. I have 57,000 KM on my 08 & other the temp issues after a scheduled coolant change it has run problem free, knock on wood!! Ron

[@350tiger]

I believe it is due to heat soak from the exhaust manifold. I actually just finished a bolt-in heat shielding for the water pump, steering reservoir and the gap that leads to the battery. Sent off the request for 25 of each to be produced of each and should have them in a week ... I have a video in the que describing the heat shield and the rational. I tried to get some other Kappa owners to do some heat measuring for me but it seems not everyone is as motivated as me to resolve some of these things. Ron if you have a kappa and a laser thermometer I would love some help ... I will send a prototype version for your troubles... if interested connect with me on FB or message me and I will send more info.

[@ronlebert4245]

@@350tiger Hi Tim that would be very cool!! No pun intended. Contact me @ [e-mail] Ron

[@350tiger]

Ron ... so I was out for a drive tonight and you are right ! 1000-2500 rpm while better than before yields 198-205 but drop a gear and get revs 2500-3000 and temp drops to 185 almost instantly ... seems we have a very inefficient impeller design on some cars. I did not three different impellers and the one from ACDelco looks the most efficient. I think it is a case of poor low rpm transfer of fluid due to poor pump design.

[@hochgonzalo8923]

Consider yourself awesome, Tim. I'm picking one up on my day off.

[@sramBC]

I’ve been fortunate here in flaming west Texas August temps. Thanks for your time and sharing of information!

[@350tiger]

SRAM super hot for here in So Cal as well at 100-105 ... but only 86 today. I will be doing another mountain run and evaluate the results then ... it looks promising that I have improved the cooling efficiency.

[@strobe54]

Tim, very insightful. Thanks for the explanation and demonstrations.

[@350tiger]

Glad it was helpful John

[@johntilton1630]

Bravo! Very informative. I wish I had the time and patience but we all appreciate you Tim !

[@350tiger]

Thanks John !

[@bbb462cid]

Tim! Yesterday I was hoping you had done a video on replacing the LNF's crankshaft position sensor. Turns out you can do it without getting under the car, just remove the turbo hose on the driver's side and you can see it, and even touch it with your finger. GM procedure is to remove the starter and get at it from underneath. No thank you GM! Keep up the good work Tim.

[@350tiger]

That is great feedback ! I have not had to do that ... YET ... but I appreciate the tip very much!

[@bbb462cid]

@@350tiger glad I might have helped. The M car manuals are great but sometimes, there's another way!

[@sicmaggoter]

Im having the exact same problem. Temp would rise to 210,then drop,but that doesn't seem right to me. Sadly,everyone kept telling me "thats normal" and i don't have the knowledge to search the issue further myself. Thanks for the extremely informative video,keep em coming. Hails from greece

[@350tiger]

210 is not catastrophic as these cars are designed to stay OVER 190 based on the fan adjustment options within the computer. My car on the drive last night went to 207 but stayed very consistent between 197 and 203. I left it idling in my driveway for 20 minutes and it got to 210. A short rev up to 3000 and it dropped to 194 very quickly. It seems these cars do not circulate coolant well below 2500 RPM. Another comment above gave some great insight into the engineering that requires these cars to get some RPM over 2500 to effectively circulate the coolant and cool properly.

[@350tiger]

Check out Ron Lebert’s comment below ... he offers an excellent insight.

[@350tiger]

Also make sure you have purged the cooling system well. If temp is swinging more than 10 degrees I would try the East purge method in Tim’s Garage Episode 20 as it is really easy to do!

[@skipperrichman4278]

Thanks I knew there was a difference

[@onlywenilaugh6589]

Boiling is pretty hot. I wonder how much a higher flow radiator replacement would help.

[@danieljohnson5174]

You convinced me it's time to buy a new thermostat. Our 09 has been running 5 to 10 degrees higher than normal this summer, and sine I bought it new, I know it's on the original thermostat. I imagine many Kappa owners only drive their cars during the summer so I'm wondering how much a thermostat deteriorates just by sitting in the garage.

[@350tiger]

Well I cannot answer that but my car was acquired at 6000 miles 2 years ago and currently has 10,100 and I would think it would last longer. The fluke of the spring rotating and causing some binding is to me an engineering oversight and should NOT be the result of a failure

[@350tiger]

Use the opportunity to also change the coolant if it is 11 years old

[@848evo4]

I have owned my GXP for 11 years and have not had any cooling issues and I live in a very warm area in the south. The only issue my car has ever had is a leaky axle seal once. 330whp 375trq so not exactly stock either.

[@350tiger]

Awesome it seems many struggle with that

[@mrbluecatone]

What the AC DELCO part number, I tried to search the number on the box but it doesn't come up. I found 131-158 and 12622410

[@350tiger]

The ACDelco water pump number is ACD# 252-821 and the GM part number is GM#89036356 …. the thermostat number is ACD #12T103D the GM part number for the t-stat is GM# 19137281

[@mrbluecatone]

@@350tiger Thanks.

[@bloodpoolyt]

i tuned my car 24# of boost and run the fans on max after 195. stays cool for the most part even with the oem radiator, i plan to go with a bigger intercooler and radiator. texas heat ive seen 226 with the AC on while under hard load regular driving 196-208 range as far as 160 - 180 temp thermostats they only matter for short runs or good cooling systems ultra fast fans and huge radiators or even dual setups, if your driving for 30mins the coolant will still reach higher temps. using 160 and 180 on some cars its almost like running no thermostat at all which just heat soaks the coolant not giving it time to cool off in the radiator efficiently

[@350tiger]

You make great points. The thing I have identified is that the Kappa Tenpnsensor is really inaccurate and on my car is anywhere from 20 to 25 degrees too high

[@Mike_Atwell]

Are you sure it's not the fan controller. Seems to be a common problem with these cars

[@350tiger]

I am pretty certain it is not the fan controller as it comes on as commanded by the ECU ... I did also have it come on sooner and build intensity faster as well. I will keep very close watch on it but for now I believe I have my problem resolved.

[@elgsquilliam]

Thank you for continuing to post your insight Tim. Would you please link the items in the description? I want to add them to the Kappa parts list I maintain. You can access it here: docs.google.com/spreadsheets/d/1AyIdDyvbkwzb5hbjFSWS8uKp6R7LAPFxcjr8yNSMSGY/edit?usp=sharing

[@350tiger]

I am not sure what you want me to do ? Did you want me to post a link to the parts on amazon or post my spreadsheet or something else ? If I link the parts as soon as they change the listing it will disappear I think.

[@350tiger]

William I have a large parts list I could email you

[@mattman63]

@@350tiger I just bought a 2008 Solstice GXP w/63K. It’s a real beauty! I’ve been hooked on your videos, thank you! I’m not a mechanic, just an enthusiast that just wants to learn more about the car. The previous owner performed a lot of work on it but I plan on upgrades as well as some PM work. If you could email the parts list that’d get great. [e-mail]. Thanks again.

[@350tiger]

Matthew I emailed you the list