Engine Temp Drop During Driving

Discuss any maintenance you've done to your Vibe & Matrix and ask how to perform maintenance on your vehicle
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clownshoes
Posts: 45
Joined: Fri Jun 25, 2010 2:15 am
Location: Ottawa Canada

Engine Temp Drop During Driving

Postby clownshoes » Tue Jan 02, 2018 6:21 am

Ok, I had a bit of leak in the rad and I used some stop leak. Worked great. This was in the spring of 2017.

Now that its -13°F out, when I drive my temp never really goes up and when I drive it drops drastically.

Should I flush out the old coolant? Do I have a stuck thermostat?

Any and all help appreciated.
2005 Pontiac Vibe AWD

andrewclaus
Posts: 126
Joined: Tue Oct 03, 2017 6:38 pm
Location: Golden, CO

Re: Engine Temp Drop During Driving

Postby andrewclaus » Tue Jan 02, 2018 6:51 am

It sure sounds like the symptoms for a stuck thermostat, but I've never heard of a stop-leak product causing that.

New coolant will cost about US$40. You also might want to replace the radiator while it's drained. It looks like you can get one for about US$60. Hopefully the stop-leak didn't affect your heater core.

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clownshoes
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Joined: Fri Jun 25, 2010 2:15 am
Location: Ottawa Canada

Re: Engine Temp Drop During Driving

Postby clownshoes » Tue Jan 02, 2018 8:06 am

The heat is fine when it heats up. Its when I get on the highway and the temp drops to nothing.
2005 Pontiac Vibe AWD

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vibrologist
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Location: Iowa

Re: Engine Temp Drop During Driving

Postby vibrologist » Tue Jan 02, 2018 9:33 am

Stuck thermostat. The stop leak may have contributed to this. In general I suggest to stay away from the stop leak stuff because it can coat the Engine Coolant Temperature Sensor and make it send wrong data to the computer.
Vibrologist
'05 Vibe

"It is important to know the difference between 'accurate' and 'precise' even if you are neither!"

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clownshoes
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Location: Ottawa Canada

Re: Engine Temp Drop During Driving

Postby clownshoes » Tue Jan 02, 2018 10:52 am

Power flush?
2005 Pontiac Vibe AWD

jolt
Posts: 569
Joined: Sun Mar 02, 2014 2:07 am

Re: Engine Temp Drop During Driving

Postby jolt » Tue Jan 02, 2018 11:45 am

Replace thermostat and cross your fingers that that the other cooling systems components did not get plugged up too. Flushing is not going help with the stop leak at this point. I have seen stop leak mess up heater cores in the past and the only way to get them to transfer heat properly was to replace the heater core. If your radiator has or had a leak, replace it. Stop leak is a band aid, not a fix. Be sure to use a good top of the line thermostat. Do not try to go cheap on a thermostat as it will cost you more in the long run. Cheap thermostats will not last more then two years at most in cold weather conditions. Thermostats do wear out or get weak over time. They should be replaced with every coolant change service for best engine fuel mileage and performance.

Capt.Vibe
Posts: 142
Joined: Thu Aug 13, 2009 7:18 am
Location: Montreal, QC

Re: Engine Temp Drop During Driving

Postby Capt.Vibe » Tue Jan 02, 2018 7:07 pm

Stop leak damage aside and not sure what year your car is, this is perfectly normal for a Vibe in -25c. If this coincidentally began as soon as the temperatures dropped into the deep freeze, read on..

Being in QC, I've experienced this on my car pretty much every winter a few times with extreme cold. The 1.8 takes a long time to heat up and the 2009-2010 Vibes have way too much grill ventilation which leads to convection heat loss once you get on the highway. There is a reason you see every tractor trailor with a complete grill block in the winter in these parts. If you're engine hasn't been running for more than 15-20 minutes it is not fully warm in -25c, and you have your heater full hot, your fan is on high speed and you don't have a grill block, your coolant temp will indeed drop and the air will start getting cooler.

Steps to combat this...

1) Do a grill block of the entire front end, both kidneys and the inlet below.

2) Let the car idle for 2-3 minutes before you drive off when it is that cold.

3) Keep the fan off and resist the urge to turn it on until the coolant temp gauge is close to the middle. When it gets there, only turn it up to 2

4) If you're running the original factory coolant you get a 50/50 mix on the assemble line. Toyota offers a 55/45 mixture for our cold climate. Get a flush done at a Toyota dealer or DIY using Toyota Super Long Life 55/45. Toyota charges less than $100.

Also, I had the upgraded Denso starter (28100-0T051) installed as my OEM starter was grinding in the cold weather. Amazon sells them for a very reasonable price. I highly recommend anyone in very cold climate gets the upgrade. It is absolutely night and day in terms of cranking speed. Barely turns over and fires on the spot even in -25c..
2010 Red Hot Metallic 1SA


jolt
Posts: 569
Joined: Sun Mar 02, 2014 2:07 am

Re: Engine Temp Drop During Driving

Postby jolt » Wed Jan 03, 2018 11:36 pm

My 2009 Vibe with the 2.4L kicks heat out like crazy. I would have to say that it is the warmest and quickest heating car I have ever seen. It is -25°C here now and that car starts heating in less then a half mile down the road. It is a big difference from what you are saying about the 1.8L engine.

andrewclaus
Posts: 126
Joined: Tue Oct 03, 2017 6:38 pm
Location: Golden, CO

Re: Engine Temp Drop During Driving

Postby andrewclaus » Thu Jan 04, 2018 5:09 am

I haven't tried the grille block in many decades with a gas engine because last time I did it (on my 70s pickup), it overheated badly when I let it idle for ten minutes or so in stopped traffic. That's a risk you may run if you mess with the radiator, depending on your driving.

A diesel mechanic told me diesels idle cooler than gas engines and it's a better idea for them. They also have a thermostat on the louvers. I just did a search and they're called 'active griller shutters.' Some cars are coming equipped with them now.

Capt.Vibe
Posts: 142
Joined: Thu Aug 13, 2009 7:18 am
Location: Montreal, QC

Re: Engine Temp Drop During Driving

Postby Capt.Vibe » Sat Jan 06, 2018 8:02 am

andrewclaus wrote:I haven't tried the grille block in many decades with a gas engine because last time I did it (on my 70s pickup), it overheated badly when I let it idle for ten minutes or so in stopped traffic. That's a risk you may run if you mess with the radiator, depending on your driving.

A diesel mechanic told me diesels idle cooler than gas engines and it's a better idea for them. They also have a thermostat on the louvers. I just did a search and they're called 'active griller shutters.' Some cars are coming equipped with them now.


Well, there could have been something wrong with your cooling system or fan or it could have been a mild day. Even with a a complete grill block the engine has room to breath from the wheel wells and underside plus the cooling fan pushing ice cold air. I've been blocking the grill on my Vibe every year and don't remove it until late March. Never an issue and the coolant gauge doesn't move from the mid point. This morning it was -23c here, even leaving the Vibe idling all day it would not overheat. After starting it took about 8 minutes for the coolant gauge to get to it's mid point and this is without using the heat in the car. I can't speak for the 2.4L but the 1.8L produces very little heat. Personally, I find the size of the radiator in the Vibe a bit overkill for such a small engine given the large amount of grille openings. It is nearly as large and as wide as my G35. My 98 Civic EX had a radiator 1/2 the size of the Vibe yet never overheated.
2010 Red Hot Metallic 1SA


jolt
Posts: 569
Joined: Sun Mar 02, 2014 2:07 am

Re: Engine Temp Drop During Driving

Postby jolt » Sat Jan 06, 2018 12:46 pm

If the thermostat is working properly there should be little to no coolant flow through the radiator if the engine is below the thermostat temperature rating. The size of the radiator at that point does not come into play. Your heater core is just another radiator with the heat going into the cabin instead of outside. When it get really cold out, the heater core can remove enough engine heat to keep the engine cool without using the radiator. Thermostats become weak and lazy over time and do not respond to temperature changes in the coolant as quickly as they do when new.

Blocking the grill, not the radiator, helps quicken the engine heating because your thermostat is starting to open to quickly and letting coolant flow to the radiator. Blocking the grill is, for the most part, safe to do. If you block the radiator, you have bypassed the thermostats ability to control the engine temperature and the only temperature control you had. The engine can over heat but you can somewhat manually control the engine temperature by using the heater core with the fan blower speed when the temperatures out side are really cold. There are so many factors that effect the sizing of a radiator but one of them is not how fast the engine heats up, that's the job of the thermostat.


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