High oil temp

[Maarten]

In reasonable fast city driving the oil temp get up to about 110C/230F but when I go onto the highway ~140kmh/90Mph the temp rockets up to over 125C/260F (Boost = 0.5bar/7PSI, oilpressure = 3.2bar/46PSI) then at the first exit it drops within 3/4 minutes back to 110C/230F  :?

Watertemp gauge in the cluster stays at the middle or a notch over. The gauge I use for the oiltemp is VDO with 150C dipsticksensor.

Is this normal or do I need an oilcooler?

[vanagondiesel]

YUP! You are frying it big time.  Get the aftermarket bolt on that has a small radiator with fan if possible.  

Anything over 230 for any period of time ruins oil....the clearances are increasing dramatically

[Otis2]

Not everyone would agree that you are "frying it big time".

Look at this thread:  http://www.vwdiesel.net/phpBB/viewtopic.php?p=13698&highlight=#13698

Those two guys are regularly running 130 C.  Mk1vdub even says that's his "normal" oil temperature, not just a peak.

It would be great to get a thread going that recorded a bunch of people's oil temperature averages.  Seems to be a wide disparity of opinion as to what is "normal" and what is "frying it big time".

For comparison sake, I don't usually see oil temps of more than about 113 C on my AAZ, but have been up as high as about 116 before turning on the heater (big new Passat oil cooler/warmer installed, which tends to make the coolant temps climb up after the oil temp hits 116 C).  When I'm not running it hard, oil temps are more like 105 to 107 C.

[Maarten]

The strange thing is that the watertemp seems to be stable while the oil changes a lot, I have a spare heatexchanger around, maybe mine is plugged somehow so I'm going to swap that next weekend when I'm going to change my coolant.

Ordered a VDO Vision series gauge (to match my other gauges) w/ sender last week so when that arrives I can double check the oiltemp.. it could be a flaky sender/gauge.

After all that I could still shop for an oilcooler, maybe a good thing because 124.8hp/244Nm is nice, but I want 300Nm  :lol:

I've got duckhams half-synthetic so it can handle some high temps before burning my fries (keep a close eye on the color/smell)

[QuickTD]

The strange thing is that the watertemp seems to be stable while the oil changes a lot,

I don't have an oil temp guage but my oil pressure guage tells a similar story. After a few minutes at highway speeds (120-140km/h) my oil pressure drops considerably, I'm assuming its due to heat. A few minutes on city streets and its back to normal. I wouldn't say there is anything really wrong with your stock setup, other than it might be inadequate.

 A larger exchanger helps to some degree. As he mentioned previously in this thread, Otis2 has installed the passat 2.0 PD unit on his vanagon with a fair measure of success. I like the idea of a coolant/oil heat exchanger better than an air/oil unit, it won't overcool and it brings the oil to temp quickly, which is just as important as keeping it cool. As soon as those passats start to hit the junkyard I'm going to get mine...

[Maarten]

Don't you have one on your TD? AFAIK all 1.6/19TDs are equipped with it overhere  :?: But there are more sources for those heatexchangers, mk2 GTIs/GTI 16vs and cars with the same engines should have it too.

Just a pic to check if we are talking about the same part:



When you pick on up from the salvageyard, don't forget the tube which the olifilter is screwed on (it's longer)

Found no oilcoolers on the salvageyard today  

[Master ACiD]

those coolant heat exchangers probably work good for a moderate summer climate, espically where you have a winter. it would help out alot in warming up the oil during winter times for all you northerners.

down here in south florida, where its 90F or hotter for 75% of the year, the summers have 98F weeks, and never gets below 45F in the winter, those coolant heat exchangers that go on the oil filter dont work so well.

my father had to resort to using a mazda 2 rotor oil cooler on his turbo caddy to bring the oil temps down. we have it mounted under the bumper in front of the air dam, right out there in the wind where everyone can see it. the oil cooler is huge. its bigger than most intercoolers you see. we also set up a remote mounted oil filter. this combined with the 2 rotor oil cooler means he has increased his oil capacity by many quarts. the oil pressure at idle and also at highway rpm have gained around 25lbs give or take.  
just by touching the oil cooler after a good highway jaunt, i would estimate it is keeping the oil around 180 or so.  180 probably wouldnt be very good for a northern car, becuase of the winter condensation problems of getting water in the oil, but down here its so hot that we never have condensation problems.

[Otis2]

Maarten, have a look at this thread, and check out the photo showing the relative sizes of the oil/coolant exchangers:

http://forums.tdiclub.com/showflat.php?Cat=&Board=UBB4&Number=745072&

Quick TD turned me on to this option - thanks B.

I'm running the largest of the three coolers in that photo on my AAZ.  Vehicle is a T3 Westfalia - very heavy.  New radiator & heater cores, so no coolant plugging problems.  Intercooled, and very short 2.5" mandrel bent exhaust, no cat.  Interestingly, I never see more than 1050 F exhaust gas temperature, even when the oil (or coolant) starts getting to be where I consider "uncomfortably" hot around 116 C.  But as I said above, those two guys in the UK are regularly running 130 C, so maybe I shouldn't worry so much...  Or else, maybe their engines are about to go "boom" very soon!

One big advantage of the big PD oil cooler that I've noticed is the much shorter time the engine takes to get up to operating temperature now. So I don't feel (quite) so bad about driving shorter city trips in the diesel these days.

[QuickTD]

Don't you have one on your TD?

Yes, I do, but its the smallish stock one. It is one size up from the one you pictured. AC equipped cars have a larger one perhaps? I'd still like to install the larger one from the 134hp PD passat when cheaper parts become available. It takes a lot of surface area to exchange the heat when the temp difference is relatively small, a bigger cooler helps with this.



 

those coolant heat exchangers probably work good for a moderate summer climate, espically where you have a winter.

You're probably right. I feel better about the water cooled oil cooler in the winter when it's -15ºF. We only get a couple of weeks a year in the 90's so heat is less of an issue.

[Master ACiD]

in the winter that oil cooler probably acts as an oil heater, which would be a good thing.

[Maarten]

Maarten, have a look at this thread, and check out the photo showing the relative sizes of the oil/coolant exchangers:

Ok.. didn't know that... the right one is huge  :shock:

I'm going to check my Audi A3 TDI with clima what is on that.


This is a Golf Mk1 GTI oilcooler, but this one flows oil all the time so a thermostatfunction would be a good modification:

http://members.lycos.nl/gtiwob/pics/16.jpg

[vwmike]

Those early MK1 oil coolers were in fact thermostatic (My 79 Golf has one).

[vwmike]

Another thing you might want to note is that the GTI filter flange won't fit most if not all of the AAZ's. They redesigned the filter flange and block around 1990 to incorporate an anti-drainback valve so the early style one won't bolt up. I'm not sure what years Europe got the AAZ though...perhaps there was an earlier version of it that it would work on.

[Maarten]

The filtersupport doesn't need to be changed, only the heatexchanger.. for what i've seen it is the same size as on a 1.6TD.

[Otis2]

Maarten, I thought you were suggesting that you wanted to add that GTI air/oil cooler to your existing (factory) coolant/oil heat exchanger.  To do that, you'd need to change the filter flange for that GTI one, which VWmike now says will not work on engine blocks built after about 1990.  

But if you just want to replace your existing coolant/oil heat exchanger with one of the bigger ones shown in that TDI club thread, then yes, you keep your existing AAZ filter flange.  To use that biggest PD heat exchanger on your AAZ, you just need to machine a new, longer, center "spike" for the oil filter to screw on to, because your existing one will not be long enough with that bigger heat exchanger in place.  The filter can't grab the threads.  VW doesn't make a "spike" long enough to do that job on an AAZ engine, so you have to get friendly with a machine shop or build one yourself.