Yes that is what the cooler is for. But when its hot it is less effective. This may not be the problem of low power, but it would be interesting to know what the temp of the fuel in the tank is after a long hiway ride.
Fuel temps will rise when weather is hot, that will retard timing and reduce power. I think this is more pronounced with the auto trans, that is why they have fuel coolers and manuals do not.
Hi Josh,
This is great work!
Inspired me to look thru the options available from Worldpac, the parts supplier for a shop I work with.
I found a Wahler 92 degree Celcius = 198deg F.
Fitment is 1984-1992 VW Jettas with 1.6 diesels.
VW part number: 056 151 113F
Part # on Wahler box: 4256.92D50
Its a readily available part that's higher temp than stock.
Didn't have to mod it so I just installed it in my 98 Jetta yesterday.
Thats great mileage for the 01M! Perhaps with the 5 speed you will go down to 44 haha.
There is an xgauge that does that. It's on this site somewhere, should come up on a search...Just a tid bit of info about the Scanguage temp reading. It tells you the trans fluid (on an O1M auto) temp under the normal water temp area. I didn't know this until the valve body had a problem and the torque convertor would slip and my temps ran up to about 260 on the scanguage. I think you can reprogram it so that it tells you the coolant temp, but don't know how.
Just for kicks, thought I'd check the coolant tank temp tonight. Ambient temp: 72F
Coolant temp: 190F!
so how is this different from a normal tstat function??Fellas,
If anyone has a little free time, and might be able to verify my results with a little experimention on their end I would appreciate it. Basically all I did was to take my properly functioning thermostat out of my car and heat it up to boiling temps, and cooled it back down to room temperature about 6 times in a span of 1 hour. I used the microwave, and submersed the T-stat into a Pyrex measuring cup with distilled water and turned the microwave on until boil started, and removed it until it cooled down. I reinstalled it with a new O ring, and have been logging mileage numbers since then. It might be better if someone with a scan guage would do this that way they could compare usual water temps to water temps post thermostat exercise.
This is just something I noticed after I removed my T-stat and exercised it in a boiling bath. The difference is that the boiling bath is 212 deg f and normal TDI operation would be below 200 deg f probably. In any case I think it was a fluke, and we have learned alot since then. I wouldn't recommend the proceedure you are talking about, however the construction and testing of the "hybrid"' T-stat has yielded some MPG increases.so how is this different from a normal tstat function??
this is exctaily what happens during warm up.
DF,Just thought I'd check it since when I replaced it during the cooler months, I only achived 185F or so, and I was a little disappointed.
Anyhow, I'll pick up those t-stats this weekend and get them to you. I'll send a PM to you when I mail them.
Hi Josh,
First, I want to say I pray that your wife is o.k. You and her are in my thoughts and prayers. Keep the faith.
Second, good find concerning the space behind the t-stat.
And, how did that 5 spd swap go? I envy you! lol! That's a big project.
I think you'll be really have with the 5 spd manual trans.