Boxster Overheating on its MOT
Discussion
Had the dreaded MOT today, they abandoned ship before they started as it over heated?
Its never over heated before and i had to go and pick it up as they wouldnt do the rest of the test.
I have checked the fuses and all is ok, are the cooling fans known for issues? no idea how to get to the fans to test them. i dont even want to know where the fan switch is!
any known issues with a 03 plate 2.7?
I knew i should of stayed with aircooled?
Its never over heated before and i had to go and pick it up as they wouldnt do the rest of the test.
I have checked the fuses and all is ok, are the cooling fans known for issues? no idea how to get to the fans to test them. i dont even want to know where the fan switch is!
any known issues with a 03 plate 2.7?
I knew i should of stayed with aircooled?
There's also two resistors that control the low speed fans. These deteriorate internally and the low speed then won't kick in, you will only get high speed.
Worth a check that you are getting both on.
Easiest way is to pull the relays and jump the power circuit to turn fans on and off manually. There's a relay for each side and for both speeds (so 4 in total).
If you pull the wheel arch liners you can access the fans etc to check the electrical side if needed after this.
Worth a check that you are getting both on.
Easiest way is to pull the relays and jump the power circuit to turn fans on and off manually. There's a relay for each side and for both speeds (so 4 in total).
If you pull the wheel arch liners you can access the fans etc to check the electrical side if needed after this.
Edited by fioran0 on Monday 15th October 19:40
Yeah, entire line up. Most cars only have high speed left and don't realise. I'd wager that almost every 9X6 that's not had them replaced already will have them not working.
The resistors clip to the rad/fan frame and look like a metal cigar.
Replacements are a rip off but there's little alternative. You splice them in. Let me know if you need PNs or more info.
See my add to the post above. Look for the 4 fan relays. Jump the power side on the low speed with a wire and see if fan turns on.
The resistors clip to the rad/fan frame and look like a metal cigar.
Replacements are a rip off but there's little alternative. You splice them in. Let me know if you need PNs or more info.
See my add to the post above. Look for the 4 fan relays. Jump the power side on the low speed with a wire and see if fan turns on.
Edited by fioran0 on Monday 15th October 19:51
vwsurfbum said:
good news/ bad news.
Fan is working (first time i ever heard it on the way home) but its running with neadle in the dead centre.
so i think it maybe a water leak, never noticed anything before, but i'm topping it up and its going down very slowly?
A coolant gage needle in the center of its travel doesn't mean the engine is overheating. The dash warning lights are used to signal an over temp condition, a low coolant level, or a non-functioning engine compartment fan.Fan is working (first time i ever heard it on the way home) but its running with neadle in the dead centre.
so i think it maybe a water leak, never noticed anything before, but i'm topping it up and its going down very slowly?
'course if the needle really climbed way above where it normally hangs out I'd probably not wait for the lights to come on but pull off somewhere and investigate.
Also, IIRC the radiator fans should come on low speed at a coolant temp of 212F and shut off if the coolant temp drops to 205F. If the coolant temp continues to go up to 216F the fans switch to high and do not shut off until 205F.
I've driven my 02 Boxster in high ambient temps with the actual coolant temp reading 226F for long (several hours) with no ill effect to the engine. I can't recall where the temp gage needle was my eyes were on the OBD2 code reader/data viewer and the intake air temp (135F) and the coolant temp. But I'm sure no warning lights ever came on.
Heck even on mild days sitting in a long line of cars waiting my turn to the drive through pick up window for my order the coolant temp can climb to the point the fans come on low speed. The coolant gage needle is not quite straight up but it is close to straight up.
But that ain't overheating.
Sincerely,
Rockster.
From my understanding of the MOT testers, it dumped its coolant all over the floor whilst getting very hot.
Looking myself, it looks like it has developed a water leak coming from the O/S/R wheel, weather it was caused by getting very hot or the water leak caused it to get very hot we'll never know.
So today i'll have to find a garage to investigate as i'm now at work until saturday with no time to do it myself and i go away on holiday next week!
Grrrr.
Cheers for your help chaps.
Looking myself, it looks like it has developed a water leak coming from the O/S/R wheel, weather it was caused by getting very hot or the water leak caused it to get very hot we'll never know.
So today i'll have to find a garage to investigate as i'm now at work until saturday with no time to do it myself and i go away on holiday next week!
Grrrr.
Cheers for your help chaps.
Hi,
It may just be a faulty coolant pressure cap. Check the last two digits of part number as the cap has been updated around 5-6 times now.
Latest cap number off memory ends in 04
If yours ends 00 then chance it could be that.
Get it checked out by someone and remember the 986/996 platform is a bit tricky to bleed the cooling system after any work has been done on it.
It may just be a faulty coolant pressure cap. Check the last two digits of part number as the cap has been updated around 5-6 times now.
Latest cap number off memory ends in 04
If yours ends 00 then chance it could be that.
Get it checked out by someone and remember the 986/996 platform is a bit tricky to bleed the cooling system after any work has been done on it.
jackwood said:
anonymous said:
[redacted]
How do you do this, exactly?vwsurfbum said:
From my understanding of the MOT testers, it dumped its coolant all over the floor whilst getting very hot.
Looking myself, it looks like it has developed a water leak coming from the O/S/R wheel, weather it was caused by getting very hot or the water leak caused it to get very hot we'll never know.
So today i'll have to find a garage to investigate as i'm now at work until saturday with no time to do it myself and i go away on holiday next week!
Grrrr.
Cheers for your help chaps.
If O/S/R refers to the right rear wheel in UK speak that's what my 02 Boxster did when the coolant tank split.Looking myself, it looks like it has developed a water leak coming from the O/S/R wheel, weather it was caused by getting very hot or the water leak caused it to get very hot we'll never know.
So today i'll have to find a garage to investigate as i'm now at work until saturday with no time to do it myself and i go away on holiday next week!
Grrrr.
Cheers for your help chaps.
What proved to be a bad coolant cap all that happened was the coolant level just got low over time until the warning light came on. A top off and a cleaning of where the cap screws down and a new cap had that issue resolved.
Sincerely,
Rockster.
Rockster said:
vwsurfbum said:
From my understanding of the MOT testers, it dumped its coolant all over the floor whilst getting very hot.
Looking myself, it looks like it has developed a water leak coming from the O/S/R wheel, weather it was caused by getting very hot or the water leak caused it to get very hot we'll never know.
So today i'll have to find a garage to investigate as i'm now at work until saturday with no time to do it myself and i go away on holiday next week!
Grrrr.
Cheers for your help chaps.
If O/S/R refers to the right rear wheel in UK speak that's what my 02 Boxster did when the coolant tank split.Looking myself, it looks like it has developed a water leak coming from the O/S/R wheel, weather it was caused by getting very hot or the water leak caused it to get very hot we'll never know.
So today i'll have to find a garage to investigate as i'm now at work until saturday with no time to do it myself and i go away on holiday next week!
Grrrr.
Cheers for your help chaps.
What proved to be a bad coolant cap all that happened was the coolant level just got low over time until the warning light came on. A top off and a cleaning of where the cap screws down and a new cap had that issue resolved.
Sincerely,
Rockster.
edc said:
jackwood said:
anonymous said:
[redacted]
How do you do this, exactly?vwsurfbum said:
Yep, pretty sure after wasting a day of work yesterday this is what it is. looks like i have the old cap on it. so no leaks at the moment and i'll purchase a new cap
As long as the new cap comes attached to a new coolant tank -- a bad cap can't account for the gush of coolant that was described.Sincerely,
Rockster.
Mine was fine until I was queuing for a car wash with the hood down & switched the climate off. Within 40 seconds or so it peed quite a lot of coolant out the header. After a lot of mucking around & diags by an OPC it emerged that the DME wasn't triggering the fans properly. The engine sensor triggers the DME input which drives the relays.
But with the climate on the fans run anyway so would have masked the problem. Jon Mitchell has experienced the same problem on a 996 & had the DME fixed by his repairer for £250ish. That is where my DME will be going once I manage to take it off the road.
But with the climate on the fans run anyway so would have masked the problem. Jon Mitchell has experienced the same problem on a 996 & had the DME fixed by his repairer for £250ish. That is where my DME will be going once I manage to take it off the road.
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