Author Topic: Changed my thermostat to one of the coldest... (Read 7000 times)

jtanguay · « **on:** April 29, 2007, 07:32:51 pm »

Well I changed my thermostat after finding out that the dealer one was crap... so I got the coldest one out there (i'm just driving with the motor for the summer...)

now there is white smoke under load... no black! please tell me that it is because I have the cooler t-stat

will it hurt my motor any? doesn't seem to affect performance much at all...

thanks

burn_your_money · « **Reply #1 on:** April 30, 2007, 06:08:26 am »

What is your timing set at?

jtanguay · « **Reply #2 on:** April 30, 2007, 10:22:38 am »

around 1.06

Doug · « **Reply #3 on:** April 30, 2007, 04:16:45 pm »

Didn't you have overheating issues earlier this year? I'll bet that it is head gasket time.

RabbitJockey · « **Reply #4 on:** April 30, 2007, 06:13:05 pm »

head gasket time is the best

jtanguay · « **Reply #5 on:** April 30, 2007, 11:41:25 pm »

i doubt it's my hg... but maybe it finally went in the past few days... i was able to get black smoke today.. weather was pretty nice out, which is what i'm thinking...

yea funny how my overheating problem was the thermostat... what a total piss off!!! oh well... lesson learned!

jtanguay · « **Reply #6 on:** May 01, 2007, 11:22:11 am »

hmmm that white smoke might have been from the cold night... with humidity perhaps???

no more white smoke... all black now...

i do have minor diesel leaks on the injectors and return hoses though... that would account for the harder than normal starts (sputters a little bit, but she catches usually on the first crank)

i also have smog's gtd injectors with 160 bar breaking pressure... i have a feeling that could be my problem as well... i have noticed better mileage with the rebuilt injectors, mainly because one of my old ones had a bad heat shield... i'd say around 50 extra km per tank now...

since the thermostat is such a cold one, i think its cooling off the head way too early... leaving the pre-chamber colder and not able to properly burn the fuel... that's my hypothesis anyways!

Doug · « **Reply #7 on:** May 01, 2007, 03:14:15 pm »

Ya! Ya! I think That you are in head gasket denial!!

Vincent Waldon · « **Reply #8 on:** May 01, 2007, 04:20:40 pm »

The difference between a "hot" thermostat and a "cold" thermostat is... 20-30 degrees F ? And this temperature setting is only really telling you when it starts to open... it can get hotter all it wants, up to the limits of the rad, fan, airspeed, ambient temp, etc.

And, it pales in comparison to the 900 degree combustion temperature inside the prechambers in the head (can you tell I just read the Bosch diesel book, fourth edition !!!).

All that being said, it's probably wishful thinking that your head is now too cold !!!

jtanguay · « **Reply #9 on:** May 01, 2007, 08:40:31 pm »

well i mean this thermostat is really cold... lol i dont think you understand... i was able to blow white smoke out of my tailpipe on the highway under load :roll: :lol: (it was a very windy and chilly night... temp gauge was at 1/4)

the t-stat opens at around 160F... when i start up the engine.. let it run for about 1 minute, the rad starts getting warm...

i had the same issues with an old jetta of mine... had to drive 120km/h on the highway to get any sort of heat in the winter.

dear god what have i done! lol...

btw my coolant level isn't going down...

i do have the 1.9 metal HG... i just find it too coincidental having these issues after changing the t-stat...

Vincent you do make a good point about the 20-30 deg F, but the fact that the t-stat is pretty much just staying open leads me to believe that this differential is make more of a difference than it would seem. i will continue to drive it, and until i see coolant dropping, i will continue to deny any HG issues :lol:

Vincent Waldon · « **Reply #10 on:** May 01, 2007, 11:07:57 pm »

It *is* very suspicious that this all started when you changed your stat....and you have a temp gauge that tells you your engine is much cooler as well.

Hmmmmmmmm... perhaps more evidence will present itself...

Darth Garry · « **Reply #11 on:** May 10, 2007, 08:49:30 am »

The thermostat makes a big difference on how the engine will perform. I would say that under any normal circumstances, go with the normal "stock" temp thermostat (87 degrees I think). I put an 80 degree in my truck because of all the desert driving I did a few years back and I believe running the motor cooler will lower its efficiency and make for more parts wear.

Not to mention less heat.

Garry

jtanguay · « **Reply #12 on:** May 10, 2007, 12:48:18 pm »

yeah... well doesn't a lower temp t-stat have lower wear??? all those high performance engines use the coldest t-stat available right??? i'm only going to be driving the car in the summer with this t-stat, so that should be okay right???

btw... i have no overheating issues... car is running excellent! i am getting a bit of white smoke out the tailpipe on hard acceleration though...

clbanman · « **Reply #13 on:** May 11, 2007, 03:08:42 am »

According to a chart published in an older Popular Mechanics, if your engine coolant temp drops from 160 to 100 degrees F, cylinder wall wear increases by a factor of 3.

jtanguay · « **Reply #14 on:** May 11, 2007, 03:19:56 am »

Quote from: "clbanman"

According to a chart published in an older Popular Mechanics, if your engine coolant temp drops from 160 to 100 degrees F, cylinder wall wear increases by a factor of 3.

and this is why people are instructed to drive their cars immediately from cold??? :?

my t-stat is a 160F i'm pretty sure... it'll be fine for summer.

i wonder if the wear is from lack of proper lubrication, or metal parts not having expanded enough, causing 'loose' tolerances?

Author Topic: Changed my thermostat to one of the coldest... (Read 7000 times)

Doug

Doug