We went away for this past weekend with my caravan (trailer) not a particularly big or heavy van. On uphills under load the engine temperature went very high, up to just before the red zone. Going there the outside temperature was not very hot about 18c and coming home about 30c. However the problem did not appear to be much worse when the outside temp was hotter. Without the van the temperature remains constant with hardly any variation.
Once I crested a hill and the load was reduced the temperature dropped to normal levels quite quickly.
The car has been serviced recently and all the fluid levels are ok, except that when I arrived home I checked the oil level and it appeared to be significantly over filled. This evening I drained some oil out and landed up draining about 1.5 litres out in order to get the oil level reading to just below the high mark on the dipstick.
I am taking it in on Thursday to get the radiator checked and a full flush, etc.
However, my question is, if the engine oil is over filled by so much can this cause the temperature to rise and if so, so high? I expect the temp to rise under load but not to such an extent!
Engine temperature rises very high under load
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Chris Steffen
- Posts: 27
- Joined: Thu Nov 07, 2019 11:53 am
- Location: Cape Town, South Africa
When pulling my rig with my VQ40, the engine temps can get up to 230F when ambient temps are high, but thats not enough to make the engine coolant temp gauge move to show its overheating (i measure using a scan tool).
Does your gauge move? If so, are you able to measure the actual temps with a scan tool, and give us that info?
A review of the Field Service Manual may be in order, to determine if a fault condition is present, or if this is just normal operating.
SMJ, as always, is spot on, 1.5L overfill of oil wouldn't cause this.
t
Does your gauge move? If so, are you able to measure the actual temps with a scan tool, and give us that info?
A review of the Field Service Manual may be in order, to determine if a fault condition is present, or if this is just normal operating.
SMJ, as always, is spot on, 1.5L overfill of oil wouldn't cause this.
t
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Chris Steffen
- Posts: 27
- Joined: Thu Nov 07, 2019 11:53 am
- Location: Cape Town, South Africa
Thank you. Yes the guage moves to the top just before/on the first mark. It does not go into the "red" zone.
I wondered whether the atf was heating up excessively under load and in turn heating up the coolant, however I have just been crawling under the car in the dark and as far as I can see the atf is not routed through the radiator as it is on some models. As far as I can see it has it's own atf cooler mounted low down in front of the radiator beneath the intercooler. I have not taken off any of the plates beneath to check properly though.
I am taking it in on Thursday to a radiator specialist so will see what they say. Will give feedback.
I wondered whether the atf was heating up excessively under load and in turn heating up the coolant, however I have just been crawling under the car in the dark and as far as I can see the atf is not routed through the radiator as it is on some models. As far as I can see it has it's own atf cooler mounted low down in front of the radiator beneath the intercooler. I have not taken off any of the plates beneath to check properly though.
I am taking it in on Thursday to a radiator specialist so will see what they say. Will give feedback.
Your radiator also might simply be old getting a bit clogged and losing its ability to bleed off heat at the environment.
One trick from the street race community I was a part of many years ago was:
-to refill the raditor with a thinner mix ( instead of 50/50 coolant/distilled water maybe closer to 40/60. If you are using premixed coolant then dont top it off with premix but top it off with distilled water.
This increases the heat capacity of the radiator effectively enlarging it a bit
- but the above has to be in conjunction with adding a bottle of this product
https://www.sandtler24.de/red-line-wate ... o4EALw_wcB
What this does it changes the surface tension of the coolant. Resulting unless bubble formation at the cooling fins inside the radiator and hence better heat transfer. Also it is said to reduce cavitation at the water pump.
Lot of street racer folks who run stock radiators but added after market turbos do this little trick to avoid buying/installing bigger radiators.
What are the tradeoff? A thinner mix will have to be replaced more often is more susceptible to boiling over at a given temp. but enough people whose judgement I trust do this. I have also done this many times when running stock radiator in a 350Z and with supercharger take the power from 300 at the crank to nearly approx 480 at the crank.
So I figure this trick may help an old radiator transfer heat more effectively.
One trick from the street race community I was a part of many years ago was:
-to refill the raditor with a thinner mix ( instead of 50/50 coolant/distilled water maybe closer to 40/60. If you are using premixed coolant then dont top it off with premix but top it off with distilled water.
This increases the heat capacity of the radiator effectively enlarging it a bit
- but the above has to be in conjunction with adding a bottle of this product
https://www.sandtler24.de/red-line-wate ... o4EALw_wcB
What this does it changes the surface tension of the coolant. Resulting unless bubble formation at the cooling fins inside the radiator and hence better heat transfer. Also it is said to reduce cavitation at the water pump.
Lot of street racer folks who run stock radiators but added after market turbos do this little trick to avoid buying/installing bigger radiators.
What are the tradeoff? A thinner mix will have to be replaced more often is more susceptible to boiling over at a given temp. but enough people whose judgement I trust do this. I have also done this many times when running stock radiator in a 350Z and with supercharger take the power from 300 at the crank to nearly approx 480 at the crank.
So I figure this trick may help an old radiator transfer heat more effectively.
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Chris Steffen
- Posts: 27
- Joined: Thu Nov 07, 2019 11:53 am
- Location: Cape Town, South Africa
Thank you for that advice, I will look at that if the problem persists. Some feedback thus far, the radiator shop called to say that they found that half the radiator was blocked after they removed it and took the top tank off. I get it back on Friday so will try and test it this weekend up some long hills near where I live.
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Chris Steffen
- Posts: 27
- Joined: Thu Nov 07, 2019 11:53 am
- Location: Cape Town, South Africa
Some feedback and as a note of caution.
I received my car back last week Friday from the radiator specialist. I was informed that the radiator was about two thirds blocked, apparently this is quite common with cross flow radiators. So I merrily drove off to office but on my commute and on Saturday I noticed the gearbox being jerky/rough, certainly not behaving normally. I also noticed the AC was not working.
I decided to check the atf level and it did not even register on the dipstick. Now the car has just had a service about 2000km ago so I assume the level would have been checked and topped up then by the garage.
While I am checking the atf level I notice the following:
The AC pump is not switching on
An AC actuator switch on the condenser is broken
The AC condenser is not bolted back properly
The turbo pipe leading to the intercooler is not bolted back properly
The whole radiator is not fixed securely
The bonnet/hood close switch is dangling on its wires
Some of the bolts holding the plates on the underside are now missing
I top up the atf with about 750ml (dexron 3, all I had over the weekend) and still cannot see the atf register on the dipstick. I took the car back on Monday very unhappy with them and told them to sort it out. The workmanship was just plain shoddy and I was very unhappy with them. Nevertheless, they fixed all the issues. But i told them not to top up the atf.
I bought some Matic J from Nissan yesterday (cost an arm and a leg) and drained the atf this evening. 2.5l drained out. I then filled with 3l of fluid. Which means that it must have been about 1.25l underfilled.
I imagine when they disconnected the atf coolant pipes from the radiator, the fluid drained out. They may have also disconnected the atf cooler to get the radiator out and allowed fluid to drain there as well.
Moral of the story; know your car and check your repairs yourself, etc.
I received my car back last week Friday from the radiator specialist. I was informed that the radiator was about two thirds blocked, apparently this is quite common with cross flow radiators. So I merrily drove off to office but on my commute and on Saturday I noticed the gearbox being jerky/rough, certainly not behaving normally. I also noticed the AC was not working.
I decided to check the atf level and it did not even register on the dipstick. Now the car has just had a service about 2000km ago so I assume the level would have been checked and topped up then by the garage.
While I am checking the atf level I notice the following:
The AC pump is not switching on
An AC actuator switch on the condenser is broken
The AC condenser is not bolted back properly
The turbo pipe leading to the intercooler is not bolted back properly
The whole radiator is not fixed securely
The bonnet/hood close switch is dangling on its wires
Some of the bolts holding the plates on the underside are now missing
I top up the atf with about 750ml (dexron 3, all I had over the weekend) and still cannot see the atf register on the dipstick. I took the car back on Monday very unhappy with them and told them to sort it out. The workmanship was just plain shoddy and I was very unhappy with them. Nevertheless, they fixed all the issues. But i told them not to top up the atf.
I bought some Matic J from Nissan yesterday (cost an arm and a leg) and drained the atf this evening. 2.5l drained out. I then filled with 3l of fluid. Which means that it must have been about 1.25l underfilled.
I imagine when they disconnected the atf coolant pipes from the radiator, the fluid drained out. They may have also disconnected the atf cooler to get the radiator out and allowed fluid to drain there as well.
Moral of the story; know your car and check your repairs yourself, etc.
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Chris Steffen
- Posts: 27
- Joined: Thu Nov 07, 2019 11:53 am
- Location: Cape Town, South Africa
Yes thanks, its all fixed. The AC control switch (not exactly sure what it does) was replaced. I did a good check after re collection to ensure all fixed and bolted. They also regassed AC.
I have not had an opportunity to do a tow test up a long hill yet (did not want to tow till I had the atf level correct), will try and do that this weekend. It's hot here now so a long haul up a hill will be a good test of the cleaned radiator.
I have not had an opportunity to do a tow test up a long hill yet (did not want to tow till I had the atf level correct), will try and do that this weekend. It's hot here now so a long haul up a hill will be a good test of the cleaned radiator.
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Chris Steffen
- Posts: 27
- Joined: Thu Nov 07, 2019 11:53 am
- Location: Cape Town, South Africa
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