Cooling Fan Coming on Late, I Think? Topic is solved

WhatAmIDoing · Post by **WhatAmIDoing** » 18 Jun 2017, 20:17

For a while now, I've noticed my dashboard temp gauge has been creeping above the 3 o'clock position. It usually peaks at the next notch up, but sometimes will go as high as 2 notches, but never gets close to the red. This happens whenever the car has come to an extended stop (stop and go traffic, parking, etc) or when traveling at low speeds (<20mph). At speeds over 35mph, I have never noticed the needle move. Not sure how long this has been happening, as I never really keep a trained eye on my temp gauge at all times. I've been trying to research this and have seen varying information, but nothing definitive. However, I have read countless times that the needle should never really stray from 3 o'clock. So this trend has me worried, although I'm not sure I should be worried.

Since I noticed this happening a couple months ago, I started paying more attention to what was going on and what I had been doing. Been driving in hilly areas a lot, which is putting the engine and turbo to work and obviously producing a lot of heat. Before every cold start, I check that the coolant is above the min line. After one such trip, I pulled off into an empty parking lot, opened the window, shut off the A/C and stereo, and listened. After about a minute or two, the needle crept up one notch and then I heard the cooling fan kick on. It stayed on for a couple minutes, the needle dropped back to 3 o'clock, and the fan shut off. After a few more minutes, I watched the temps creep up again. The fan kicked on for a couple minutes, temps went back to normal, and I watched the cycle repeat 2 more times before leaving.

Is this normal behavior, or concerning? I thought the temp needle was never really suppose to leave the 3 o'clock position, so I'm guessing this is not normal. I'm guessing one of two things is happening: something is delaying the fan from coming on, or the dashboard temp gauge is faulty (not sure how to diagnose either). My biggest concern is that this excess heat could be damaging my engine or other nearby components. Is this something I should be worried about? Is this something that needs to be fixed right away? Or am I worried about nothing?

Included a picture I took just after the fan initially came on.

Post by **abscate** » 19 Jun 2017, 01:57

Do you have a scan tool that can measure coolant temp?

My T5 cycles between 187 and 205 at idle with the fan coming on at the top and going off at the bottom of that range

The needle never moves from 3 o'clock but you should think of that gauge as a warning light not a gauge, as noted

I don't like that it is moving, possible ECT or thermostat failure?

kaneelschep · Post by **kaneelschep** » 19 Jun 2017, 12:25

Mine never ever moves more than a hair from three o clock too.
Not in traffic, hills, etc.
Few months a go we followed a friend through hairpins around his hometown in switserland for 15 minutes. Never seen a 60 year old drive a smart that fast..
That was the first time i heard the fan stay on for so long after parking.
Still needle moved almost nowhere.

Yes, Maybe your thermostat stays closed.
Taking it out to test isnt that much work.
The ect mostly gives more problems when broken. Mine made the engine rev by itself.

Post by **cmblackburn** » 19 Jun 2017, 12:33

I'd be quite wary of that. When I put a new head on my S70 was the only time I ever saw my gauge move from the 3 o'clock position, would go straight to red as there was air in the system. Just went on a 1500 mile road trip and the gauge didn't move from 3 o'clock at 95mph or in 94 degree weather stuck in traffic with my AC blasting. Check that your fan is properly working in both speeds and doesn't have broken blades or lots of resistance to turn. Have you recently replaced the coolant? You could have air bubbles.
I live in the mountains, pushing my T5 up a 13% grade when it still had air bubbles was enough to push me into the red- This was resolved by jacking the car up with the cap loose and running it for about 30 minutes. The overheating while climbing the grade (or at all) hasn't happened again

WhatAmIDoing · Post by **WhatAmIDoing** » 20 Jun 2017, 21:07

I have a simple scan tool for pulling and reading codes, but not sure if it can pull and other data.

I have not seen the coolant boiling, so I guess that's good. The coolant probably is due for a change. Do I have to use volvo coolant, or can I use something I can get at any auto parts store (such as)?

Going up many hills today for long periods at 8 pounds of boost saw the needle climb a notch above 3 o'clock. A/C off, windows down, heard the fan on all the way up. How hard is it to distinguish between the 2 speeds of the fan? I've never noticed a difference, to me it's on or off.

Noticed today when I did a warm start (needle at 4 o'clock), the engine idled high just below 1000rpm for a while like it was a cold start. After about a mile idle went back to 850rpm. How can I test the ETC and thermostat?

Post by **wizechatmgr** » 20 Jun 2017, 21:34

If it were me I'd replace the thermostat & temp sensor, then start looking further... Thermostat is likely the cheapest item to replace and likely needs it at this point anyways. Did you have rather crappy heat this winter compared to previous winters in the car? If so, that would be a trademark of a thermostat stuck open.

WhatAmIDoing · Post by **WhatAmIDoing** » 20 Jun 2017, 22:19

Heat was good, started smelling a bit sweat like antifreeze though. But looked around the heater core and didn't see any leaking. On my list to be replaced.

Post by **esl_97_850_T5** » 21 Jun 2017, 01:58

What coolant-to-water ratio have you (or a shop) measured?

Post by **abscate** » 21 Jun 2017, 06:53

WhatAmIDoing wrote: ↑20 Jun 2017, 21:07 I have a simple scan tool for pulling and reading codes, but not sure if it can pull and other data.

I have not seen the coolant boiling, so I guess that's good. The coolant probably is due for a change. Do I have to use Volvo coolant, or can I use something I can get at any auto parts store (such as)?

Going up many hills today for long periods at 8 pounds of boost saw the needle climb a notch above 3 o'clock. A/C off, windows down, heard the fan on all the way up. How hard is it to distinguish between the 2 speeds of the fan? I've never noticed a difference, to me it's on or off.

Noticed today when I did a warm start (needle at 4 o'clock), the engine idled high just below 1000rpm for a while like it was a cold start. After about a mile idle went back to 850rpm. How can I test the ETC and thermostat?

OEM only on these parts...Wahler and Volvo for Thermostat and ECT respectively

Thermostat...boil water in a pan with a thermometer. OEM Onl

ETC ...there are threads on the correct resistance as function of temperature in the VRD and in the respective Fora

Post by **jimmy57** » 21 Jun 2017, 07:10

If the low speed connector comes off its pin on fan relay then the high speed fan will be triggered at a higher temp. The plastic on those "bullet" style connectors disintegrates and the grey plastic connector body can't keep them on. Easy to inspect. Look just under that top fan shroud plastic bar for the big rectangular relay and see if the grey plastic two wire connector has a loose wire. If it is loose then push it back up on the pin on relay.