Sub Zero oil question

[Porker993]

During this prolonged period of cold weather, I can't seem to get the oil warm enough to check the level.

Yesterday, after my usual 45 minute run home from work, I couldn't get the oil temp needle to the 8 o'clock position.

Has anybody else experienced this ? Does anybody have any ideas ?

 

[clyde]

You need to give it more welly on the way home [][]. Sorry Mark, I couldn't resist the obvious answer.

I'ld leave it to idle with the lid closed, preferably in a garage where the ambient temp will be higher. Bringing the revs up to a fast idle of 2500 to 3000 rpm will speed up the process but possibly annoy the hell out your neighbours.

An alternative is to take it for a spirited drive in the middle of the day at the weekend, this is much more fun and less likely to result in domestic disputes.

 

[burrow01]

Have you checked the Thermostat for correct operation?

Maybe the front Oil cooler is open all the while, I would have thought that the heat of the engine would be able to overcome the temperatures we are having at the moment, especially as people in the Nordics etc manage to drive around in much lower temperatures

What type/weight of oil are you using?

Pete

 

[38F3E1]

20 minute run today and up to full temperature (with the needle dropping after the thermostat opening to confirm). It's below freezing here so not sure why yours isn't after 45 mins. I'm running Mobil 1 0W-40.

It does sound as if your thermostat maybe open all the time (or maybe a problem with the gauge - unlikely if it works the rest of the time).

Things to try

1/ Leave the car to idle for 10 minutes after getting home - even outside it should get up to temperature
2/ Can you feel along the driver's side sill or the front oil cooler to see if they are hot - would indicate if the thermostat is open.

Ian.

 

[clyde]

ORIGINAL: burrow01

Have you checked the Thermostat for correct operation?

Maybe the front Oil cooler is open all the while, I would have thought that the heat of the engine would be able to overcome the temperatures we are having at the moment, especially as people in the Nordics etc manage to drive around in much lower temperatures

What type/weight of oil are you using?

Pete

Worth checking the thermostat but I wouldn't be surprised if it was working perfectly, sometimes in my half hour or so journey home it doesn't open when it's really cold.

It probably depends on the driving more than anything. If the car's being driven at 30 to 60 mph in 4th, 5th or 6th for most of the way, the spoiler will be up letting all that sub-zero air flow over a motor that's only turning at 2,500 rpm tops. I've never tried closing the spoiler during a cold journey but presumably that would make a significant difference? I have opened it when the temperature gauge creeps up when I've been stuck in slow moving traffic in the summer and that does help, so the reverse should be true I suppose.

Would the weight of the oil make a difference after 45 minutes driving?

 

[Porker993]

Thanks Guys, some good things to look out for. It is worth noting there was no traffic, and I never got much over 2,000 revs. A long fast run in 5th/6th. I believe the engine never really hot. I don't have this problem when the weather is warmer.

I will leave it idling for ten minutes next time I get home, hopefully that will do the trick. Unfortunately I do not have a garage at the moment, so it will have to be outside.

If it still won't warm up next week when the weather gets warmer I will suspect the thermostat and have it checked out.

Once again many thanks all.

 

[pse_SC]

It is worth noting there was no traffic, and I never got much over 2,000 revs. A long fast run in 5th/6th. I believe the engine never really hot. I don't have this problem when the weather is warmer.

Your car must have been up to correct operating temperature after a 45 minute drive, it doesn't make any difference whether you got above 2000revs(!) or anything else. The gauge might be on the blink - they're very inaccurate at certain oil levels, anyway, and useless on the move, of course. The gauge only gives you some sort of idea when the car's been idling at rest (after a reasonable warm up run) for about 5 or 6 minutes on level ground - just as the older cars are checked. Check the oil level with the dipstick "" it's the best way; you can physically see what's going on [].

 

[clyde]

Your car must have been up to correct operating temperature after a 45 minute drive, it doesn't make any difference whether you got above 2000revs(!) or anything else. The gauge might be on the blink - they're very inaccurate at certain oil levels, anyway, and useless on the move, of course. The gauge only gives you some sort of idea when the car's been idling at rest (after a reasonable warm up run) for about 5 or 6 minutes on level ground - just as the older cars are checked. Check the oil level with the dipstick "" it's the best way; you can physically see what's going on [].

Can't agree with you there Paul.

An engine running at up to 3,500 or more rpm is going to warm up much quicker than one that is running at 2,000, especially with a sub-zero air flow over it.

The oil temperature gauge is not affected by engine speed in the way that the oil level gauge is, so it is just as accurate on the move as it is stationary.

 

[pse_SC]

Whoops, see what you mean, Clyde.

Got a bit carried away (as usual) and got mixed up with the oil level gauge. Temperature's a different thing as you say; I didn't read the post properly[]. duh!

What you say is very correct[].

I'd've thought it should be up to 8 o'clock temp after a 45 minute drive, though, even when driven at low revs?

 

[Porker993]

We know these engines are very sensitive to ambient temperature.

By the time I leave work there's always a hard frost on the car, so I'm guessing the high speed flow of freezing air must be having some effect on oil temp.

No signs of a let up in freezing temperatures yet.

Can't wait to get out there on Monday to test the theory.

I'm definitely gonna leave it idling for ten mins as Ian suggests, never mind the neighbours.

 

[IndischRot]

I do question your thermostat being stuck open. I drove my car yesterday (ambient of +2 C). Like usual I warmed it up by trundling along at no more than 3000 rpm and keeping out of the boost. Within about 15 minutes I was able to watch the temp gauge creep up to about the 08:00 mark and then drop when the thermostat opened and then creep up again to the 08:00 mark a second time.

 

[clyde]

Let us know how you get on tomorrow Mark, so we know whether to keep on theorising [].

What we'll need to know is:

1/ Average ambient temperature throughout the journey
2/ Lowest temperature recorded
3/ Highest temperature recorded
4/ Split the temperature into bands (say 1 or 2 degree increments depending on spread) and record the length of time spent in each band
5/ Average rpm for the journey
6/ Highest rpm reached
7/ As with temperature, split the rpm into bands (say 500 increments) and record the length of time spent in each band
8/ Average speed of journey
9/ Maximum speed reached
10/ As with the temp and rpm, split speed into bands and record time for each
11/ Total length of journey
12/ Anything else you think may be useful to us armchair engineers

If you can give us all the above in an Excel spreadsheet that would make the analysis so much easier [8|] [][]

Maurice, on a serious note, my thermostat has never (except perhaps on a hot summer's day) cut in after only 5 miles driving. Most of my driving when the engine is cold tends to be on open roads (with the spoiler raised), would this be the reason perhaps?

 

[Porker993]

Clyde, I'm on the case. Just a matter of manipulating the laptop while keeping the right revs.

All the best

Mark

 

[38F3E1]

Took the car out today so decided to run a test keeping the car under 3000 revs and see how long it took to open. It was minus 2 outside when I set off. Didn't go above 3000 revs at all with most of time between 2000 and 3000. Spoiler was up for most of the time. Typical speed around 60. It took exactly 15 minutes for the thermostat to open.

I'll have to try it at max of 2000 next time :- )

Ian.

 

[Porker993]

Sorry to disappoint those on tenterhooks, but following a snowfall last night, on ungritted roads, I decided to take the land rover to work.

Ian I'll try to replicate your test and see what happens. How do you know when the thermostat kicks in ? You mean when the oil temp needle drops slightly ?

 

[IndischRot]

ORIGINAL: Porker993
How do you know when the thermostat kicks in ? You mean when the oil temp needle drops slightly ?

Mine goes from the large hash mark at 08:00 down to the next lowest large hash mark and you can literally watch it drop; it takes perhaps 2 seconds.

 

[38F3E1]

ORIGINAL: Porker993
Ian I'll try to replicate your test and see what happens.  How do you know when the thermostat kicks in ?  You mean when the oil temp needle drops slightly ?

Yes the needle rises slowly to the mark at 8 o'clock as the engine warms, drops down significantly when the thermostat opens then climbs back slowly to the 8 o'clock mark again. It's very noticeable if you are watching the gauge.

BTW I tried the 2000 rpm test today when I went out and ..... sorry I just couldn't keep the car below 2000 rpm. It was too hard being that restrained ...

Ian.

 

[Taverner]

ORIGINAL: MoC2S

Likewise - mine bumped against the thermostat after no more than 5 miles of mild use .. really does sound as if the thermostat is stuck open.

cheers, Maurice [8D]

This is a really interesting thread. In my own case after a long run, albeit in warmer weather, the front and rear wings are both warm/hot obviously oil tank and oil cooler. This would indicate that the thermostat is open and oil is circulating round the whole system. Checking Adrian Streather's book he gives some info as follows. In the oil cooler thermostat there is a bimetallic strip that opens the internal oil valve at 83C 181F oil flow from the engine is then sent to the cooler.

Maurice has suggested that in one case the thermostat could be stuck open. My question is this, is there a particular test for the thermostat or is it just a case of warming up the engine and feeling the various pipes to see which way the oil is flowing by a rise in temperature.

In warm weather if the thermostat is stuck open I dont think there would be a problem as I would suggest oil always warm enough to circulate through the cooler. In cold weather it could be a different story as the oil may never reach the correct operting temperature.

Michael

 

[burrow01]

Hi,

I'm currently working in Hamburg

See lots of Porsches (mostly 911's []) cruising around town, including older air cooled versions which seem pretty much to be daily drivers (guys in suits driving in traffic @ 9am)

Last night was -12C (and -20 in some parts of Germany)

On my way into the office this morning I saw several 964's and 993's parked on the streets, completely covered in frost, presumably waiting for their owners to leap in them, start them up and drive off on their normal journey to work

I can't believe that the oil system would not be designed to reach normal operating temperature after a reasonable drive in the current conditions we have here, seemingly in the heart of Porsche country.

Pete

 

[Porker993]

Thanks to all who replied.

I can report that, on arriving home after my 45 minute drive, the thermostat did open as Ian has described after approx 30 seconds of idling, causing the oil temp needle to drop quite noticeably from 8 o'clock to 7.30, accompanied by a gurgling sound as the oil travelled up to the oil cooler and back.

What then happened, is that it stayed on 7.30 for quite some time. That is what I was seeing, and worrying that it was running too cold, causing me to make this post.

Eventually, the needle gradually rises, reaching almost nine o'clock after about ten minutes. It is then well hot enough to check the oil level, and the neighbours are wondering what is this throbbing monster gurgling away behind the hedge.

While driving along, at 2,500 to 3,000 revs, the oil temp needle seems to stay rock solid on the eight o'clock line.

So nothing to worry about, I hope.