High oil temp after switching to 20w50

[zakthor]

I switched to vr1 20w50 last weekend. 3 days later I was stuck in traffic and oil got hotter than I remember seeing before. I estimate 240 based on the tiny numbers on the far left of the gauge, 10:30 on my stock '79 gauge, 2/3 of the way from 9:00 to the start of the red zone. I got off the freeway as soon as I could and drove home slowly on backroads 5 or 10 minutes. The temp crept back down but was still at 10:00 when I got home, which I don't remember as normal. Then again 10:00 might have been normal when I was using 20w50 last summer. I left engine idling and misted water onto the front trombone cooler and kept spraying until engine temp dropped to 9 o' clock. Lots of steam so cooler was working but I can't tell if flow is sufficient.

The high temp oil occured as I was stuck on the freeway for 20minutes at almost a standstill. The backup occured after only a minute or so at 65mph, car was still warming up when I eased up to speed. Internet weather says max temp that day was only 79f but it felt hotter to me.

Being stuck in traffic isn't so rare for me, but I've never seen this high temperature before.

I'd gone with the lighter oil for winter because engine seemed to be dragging on startup with the 20-50 during the winter (Coldest is ~15f). Oil pressure seems very high with 20w50 on those cold start. The lighter oil turns over much easier and the temperatures seemed to stay lower. Engine seemed happier.

I've just reviewed a bunch of oil threads, oil cooling, etc. Seems like heavier oil is known to increase temp but that existing cooling should be able to manage idling 20w50 at 80f unless something else is wrong. I checked the various oil lines and don't see any dents.

Ideas?

[Tippy]

What oil before? I run VR-1 and on 100+ degree days see only about 9 o'clock on my 3.4, 7.5:1 CR.

[wjfk32]

I don't even bother driving if its in the high 80's..

VR1 user, never had a problem


Walt

[jwasbury]

Originally Posted by zakthor

existing cooling should be able to manage idling 20w50 at 80f unless something else is wrong.

in my experience this is not true. Back when my car had the original trombone cooler fitted, I observed temps climbing into the "discomfort zone" during 25 minutes of bumper to bumper stop n go traffic on the NJ Turnpike. This was in late March/April timeframe. Ambient temps in the mid 50s at most.

I upgraded to a Carerra style fender cooler with a fan. It was only marginally better, and on a hot day 80f+ I would still see temps climb up into the 220-230 range in stop n go traffic situations. On the track I'd see 240+ easily before the end of a 20 minute session.

Now I have a large front mount cooler, a 28 tube "jailbird" cooler in the fender, and now temps are very well controlled. On the hottest days I've driven so far this season in the 90s, I might have touched 220 after pulling off the highway and directly into the stop n go traffic near my urban home. The oil temp will drop rapidly once you get moving since there is so much airflow across that front mount cooler. On the track the temps stay at 210 or below.

[wjfk32]

^^^^^^

True--

Got rid of my trombone syle cooler-- changed to front cooler and added a ruf type spoiler.

[Ronnie's.930]

Originally Posted by wjfk32

I don't even bother driving if its in the high 80's..

VR1 user, never had a problem


Walt

If you lived in Texas you would only be able to drive between the months of November through February (maybe some in March). . .

[wjfk32]

^^^^^^^^^^^^

I feel your pain................

I don't think I would have a 930-unless I swithed to efi and e85 if I lived down in the south.
CIS- Is enough pain in the butt when the temps. are down..

Would have to go modern-996tt-997tt or gt3rs ......One of these days hopefully.

[zakthor]

Originally Posted by Tippy

What oil before? I run VR-1 and on 100+ degree days see only about 9 o'clock on my 3.4, 7.5:1 CR.

Whoops, forgot that fact. It was Rotella T6 5w40. I remember being surprised at the lower oil temps right after putting it in but it was in the fall so I figured it was just the colder air.

Before the Rotella I was using kendall 20w50, which I think also showed higher temps, but I've never seen the needle this high even sitting in traffic.

[Tippy]

Quote de wjfk32

I don't even bother driving if its in the high 80's..



VR1 user, never had a problem





Walt

If you lived in Texas you would only be able to drive between the months of November through February (maybe some in March). . .

Ditto!

[wjfk32]

Originally Posted by zakthor

Whoops, forgot that fact. It was Rotella T6 5w40. I remember being surprised at the lower oil temps right after putting it in but it was in the fall so I figured it was just the colder air.

Before the Rotella I was using kendall 20w50, which I think also showed higher temps, but I've never seen the needle this high even sitting in traffic.

MAYBE 15W40....

5W40 Will be a costly mistake in everyway.

[vascott01]

I have been using vr1 20-50 for several years with my 79..You may have been running a few quarts low...

I would reccomend upgrading to a fender mount or front oil cooler...these cars run much better and your engine will love you. Simple to do.

I started with a front air scoop but it does not do you any good sitting in traffic.

If you are not bookin you are cookin

[zakthor]

Oil wasn't/isn't low unless the dipstick is lying to me or maybe there's a big air bubble in the system somewhere? Engine took 11 liters and shows at just above the middle.

WRT the 5w40 oil weight I was using: both weights are logrithmically scaled with temperature so doesn't that 5 weight magically transform itself into thicker 40 weight as the engine warms? Are you saying the 5 weight is too thin for startup?

Except for this year's experiment with the 5w40 I've always used 20w50, that is 11 years with the sc and 2 with the 930, both only had the trombone cooler. I drive all year including some 90+ days last year and Ive never seen the engine temperature this high. Makes me think something new is wrong. Some set of factors made the engine hot this time. Now I think about it, could be that all that stopped traffic on wednesday heated the pavement to much higher temps, and that was the killer.

I was wondering if it might be sensible to change back to the 40 weight.

What I'm hearing back is "welcome to the club, keep using that 20w50 and get a better oil cooler."

Any other suggestions while I read up on oil cooling?

[full quack]

Been running Kendall 20-50W for over 4 years, drive the car 5 days a week, 42-65 miles a day. In the rain, sun, snow, from open roads to stop-n-go traffic. In outside temps from a lowest of 17 to the highest of 105.
I have only seen temps past 220 on a hand full of those 85+ degree occasions, and only once getting up to the heart palpation stage(on the one 105 degree day).
The oil temps have always dropped right down to normal range, within a mile or two after getting out of heavy, slow traffic.
All with stock 1984 930 oil system/coolers....have I just been getting real lucky???

Mark

[jwasbury]

Originally Posted by full quack

All with stock 1984 930 oil system/coolers....have I just been getting real lucky??

My 2 cents...it depends. Does your '84 have a radiator style cooler in the fender with a fan? Also, what is "heart palpitation stage" for you? In my car, the oil temp gauge is 210 at 9 o'clock. If it goes a bit above there briefly I don't sweat it, but if that needle is hanging solidly above 9 o'clock I am not happy. Maybe you have a different tolerance? When the oil temps are getting up to 240 on the track that really freaks me out because at that temp there is a noticeable decrease in oil pressure at high rpms.

I have verified oil temps with an IR thermometer so I have a good sense of actual oil temp vs. what the gauge says.

[full quack]

The tiny #"s just out of site on my oil temp gauge, says 200 degrees @ the 9 o'clock position.
My personal "heart palpitation stage", is at the 10 o'clock position which reads 220 degrees in tiny numbers.

My car does NOT have the radiator/fan style unit in the front fender, but it also does NOT have the 2 loop tube trombone unit either.

Mine has a unit with about 30 tubes(10 per row & 3 rows deep) each tube about 3/8" in diameter, the tubes are about 14" long, connected to a top & bottom tank, but no fan. The cooler is attached via all the stock lines, so I do not believe it to be anything after market, the fit is just too O.E.M. looking.

My car is a R.O.W. unit if that makes any difference.

Mark

[jwasbury]

Originally Posted by full quack

Mine has a unit with about 30 tubes(10 per row & 3 rows deep) each tube about 3/8" in diameter, the tubes are about 14" long, connected to a top & bottom tank, but no fan. The cooler is attached via all the stock lines, so I do not believe it to be anything after market, the fit is just too O.E.M. looking..

You have the 28 tube brass "jailbird" cooler. This was the factory "euro" cooler for a couple of years I believe. I swapped my radiator style cooler for one of those too. I think it is better since it does not rely so much on airflow. The radiator style gets almost no air in the fender as half of it is behind the headlight bucket.

[h20cooled7]

My car would run hot as hell. I got out the infared thermometer and started checking temps. Engine was hot but front mount cooler was ambient temp. Replaced the thermostat mounted in the right rear wheelwell and it will not go over 80 degrees ( My gauges are euro) on a 95 degree day!

[zakthor]

Originally Posted by h20cooled7

My car would run hot as hell. I got out the infared thermometer and started checking temps. Engine was hot but front mount cooler was ambient temp. Replaced the thermostat mounted in the right rear wheelwell and it will not go over 80 degrees ( My gauges are euro) on a 95 degree day!

When I got home I sprayed the front trombone cooler with water misted from a hose and it steamed nicely.

Thanks for the response though. That is the sort of ideas I'm looking for. I am wondering if changing the oil could have dislodged something, clogged up the lines or whatever. This forum is a terrible thing: now I want a better oil cooler, something with the surface area of Nebraska.

[timc]

Originally Posted by zakthor

existing cooling should be able to manage idling 20w50 at 80f unless something else is wrong.
Ideas?

I also do not find this to be true with stock front cooler, (trombone, carrera, and carrera with Fan). I have installed a large fan on my 86 930 with the carrera style cooler, that will come on when the temp hits around 215, and what it will do is as the fan comes on each time, it will bring the temp back down several times, basically just prolonging the eventual climb to the 240-250-300 mark if I let it. If I just continue to sit, the oil temp will be to much for the Carrera cooler with Fan, and it will just climb. Once I hit the 230-240 I either pull off or find another route, and the temp quickly comes back down to the 180-200 once I get going. This is with AMSOIL 20/50.

[axl911]

Hmmmm....technical oil question here.

5w50 and 20w50 should have the same viscosity/thickness at normal engine operating temperate right?