MK5 Golf GTI
All Things Mk5 => Mk5 General Area => Topic started by: kahunajb on May 03, 2013, 09:34:56 pm
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I've noticed that my car temp gauge gets up to 90 degrees but doesn't necessarily stay there. It can drop down to around 75-80 degrees depending on how I am driving then go back up to 90 again. I presume this is not normal. Do you think the coolant temperature sensor needs replacing?
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What sort of driving are you doing when it drops down to 75-80C?
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Sounds like the temperature sensor, should be a cheap fix.
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What sort of driving are you doing when it drops down to 75-80C?
I think it may be when I am driving slower it drops but it might just be randomly.
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I have the same issue.
Engine coolant thermostat is my first thought. Or could it be the coolant temperature sensor.
Which is easier to change and therefore eliminate?
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Engine Coolant Temperature sensor is really easy to change, but get a genuine VW one - not a cheap eBay one (I made that mistake and thought the problem still existed, changed to a VW genuine one and all is well again).
Thermostat is ~£130 to change by an indy as you need to remove the alternator to get to it.
EDIT: Check out my thread on this topic http://www.mk5golfgti.co.uk/forum/index.php/topic,62567.0.html (http://www.mk5golfgti.co.uk/forum/index.php/topic,62567.0.html)
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Engine Coolant Temperature sensor is really easy to change, but get a genuine VW one - not a cheap eBay one (I made that mistake and thought the problem still existed, changed to a VW genuine one and all is well again).
Thermostat is ~£130 to change by an indy as you need to remove the alternator to get to it.
EDIT: Check out my thread on this topic http://www.mk5golfgti.co.uk/forum/index.php/topic,62567.0.html (http://www.mk5golfgti.co.uk/forum/index.php/topic,62567.0.html)
Many thanks. Will get a VW sensor next time I'm passing.
£130 for changing the thermostat!!!! No wonder the stealer where I bought the car was not keen on changing it!
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Finally got round to changing my coolant temperature sensor however I am still having the same issue. Today when on the motorway cruising gauge was at a steady 90 however when I got to a long downhill section and engine was under less load it dropped down to 75-80 ish and once stopped in traffic went back up to 90.
Does this sound like it could be the thermostat instead?
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Thermostat stuck half open by sounds of things so yeah.
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Mine does the same, I wouldn't worry about it as most cars will tend to do this depending on ambient temperature, driving style, flat or hilly countryside etc.
As long as the car warms up withina few miles and the needle sits and returns to 90 deg. it's perfectly normal.
What's your mpg by the way ?
25-28 urban driving and 32-35 A road/motorway cruising is perfectly normal, if you're getting significantly less than this then you may well have a problem, otherwise enjoy the car !
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I had the exact same problem, replaced the coolant temp sensor and it didn't do much. Just had the thermostat changed and the problem is finally sorted. Gets to 90 degrees nice and quickly and also feels a fair bit quicker as it isn't running rich trying to get to temperature the whole time.
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Glad to hear it solved the problem. Have the same issue - If you don't mind saying, how much did you pay to have the thermostat changed?
I need to get mine done and just don't have the time to do it myself. :ashamed:
Thanks
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Kahunajb did you get to the bottom of this I'm having same symptoms as you were .
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Kahunajb did you get to the bottom of this I'm having same symptoms as you were .
Erratic readings, not dependent on engine charge, it's the temp sensor. Low readings when driving slow or downhill and normal when stopped in traffic, most likely one of the engine stats.
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My temp gauge is dropping from 90 under engine breaking when leaving the motorway coming off a slip road drops to around 80 . I've booked it in to be done while Im still under warranty but worried it's not bad enough .
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It should not deviate from 90 on the dash at all once it has reached operating temperature. The 90 on the dash covers a huge temperature range from 75 degrees up to over 100.
Once mine hits 90 on the dash it stays there, no matter what. The true coolant temperature reading can fluctuate between high 80's up to around 94 or 95 which is perfectly normal, but the gauge will stay solidly on the 90 the whole time
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The gauge definitely dips after it has been up to 90 its happening under engine breaking. I Used secret clima control setting 19.2 on a steady run it sits around 72-76,When I got stuck in traffic it went up to 87 on the digital clock. Because it doesn't dip down loads of 90 on the dash I'm concerned the dealer may say it's nothing to worry about il have to wait and see it's going in tomorrow, I think it's down on power a little aswell because of this .
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Mine does the same, I wouldn't worry about it as most cars will tend to do this depending on ambient temperature, driving style, flat or hilly countryside etc.
As long as the car warms up withina few miles and the needle sits and returns to 90 deg. it's perfectly normal.
What's your mpg by the way ?
25-28 urban driving and 32-35 A road/motorway cruising is perfectly normal, if you're getting significantly less than this then you may well have a problem, otherwise enjoy the car !
This is def not perfectly normal and no engine should do it !, the thermostat opens and closes to regulate the temp in the engine. The rad temp will fluctuate but the engine itself will be constantly regulated by the stat. The issue is with the stat, it's not opening and closing as it should.
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I will post up the outcome tomorrow after I have been to the dealership. It has only recently started doing this in say the last month I only drive the car on weekend, and things like this tend to go unnoticed when the missis only drives 5 mile to work and back each day. I just have a feeling that the dealer may not support me on a warranty claim .
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I have the same issue. Very rarely does mine get up to 90 and actually stay there for long, usually sitting around the 80 mark or thereabouts. Tempted to get a new temp sensor and see what happens.
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It will more than likely be the thermostat causing it mate
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It will more than likely be the thermostat causing it mate
What Dan_FR said. :wink:
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Kahunajb did you get to the bottom of this I'm having same symptoms as you were .
Erratic readings, not dependent on engine charge, it's the temp sensor. Low readings when driving slow or downhill and normal when stopped in traffic, most likely one of the engine stats.
One of?! Blimey.
Pretty sure mine need doing. MPG is woeful and the performance is shat off boost. Time to get my hands dirty!
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Kahunajb did you get to the bottom of this I'm having same symptoms as you were .
Erratic readings, not dependent on engine charge, it's the temp sensor. Low readings when driving slow or downhill and normal when stopped in traffic, most likely one of the engine stats.
One of?! Blimey.
Pretty sure mine need doing. MPG is woeful and the performance is shat off boost. Time to get my hands dirty!
Engines with manual gearbox have 2 stats. Engines with DSG pre-2008 (or 2007, I'm not sure) have 3 stats and from 2008 (or 2007) have 2.
Mine has 2 stats and the DSG stat was malfunctioning. I had the 2 stats and 3 temp sensors replaced during the mechanical overall. :smiley:
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Went out with a master tech today drove up hill and engine temp on dash dial was up to 90 and stayed there ,coming downhill I asked the tech to engine break and after a short space of engine breaking pretty much straight away temp started to drop off the tech continued engine breaking & got the temp as low as 70 on the dial. He agreed it's not right but was a little confused as to why this was happening under engine breaking as a thermostat will usually show symptoms of failing under load . Its booked back in next week a thermostat and temp sensor is on order so they have the parts if needed .
Just hope it gets sorted .
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The irony is that by the time he gauge in the car shows an issue it's likely been happening for a long time. The gauge will read 90 at any temp from around 77deg and up to over 100. I never saw the gauge move in my car but checked the temps with vcds and saw the temps fluctuating. But the gauge not moving. Mpg wasn't good either as the engine wasn't getting hot. Surprised the master tech relies on the gauge ! :laugh:
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Kahunajb did you get to the bottom of this I'm having same symptoms as you were .
Erratic readings, not dependent on engine charge, it's the temp sensor. Low readings when driving slow or downhill and normal when stopped in traffic, most likely one of the engine stats.
One of?! Blimey.
Pretty sure mine need doing. MPG is woeful and the performance is shat off boost. Time to get my hands dirty!
Engines with manual gearbox have 2 stats. Engines with DSG pre-2008 (or 2007, I'm not sure) have 3 stats and from 2008 (or 2007) have 2.
Mine has 2 stats and the DSG stat was malfunctioning. I had the 2 stats and 3 temp sensors replaced during the mechanical overall. :smiley:
Cheers mate. I'll get the bits in and save that job for when I do a manual decoke. The main stat on the engine block looks far more accessible with the intake out of the equation! Where is the other stat? Mine's a manual. Cheers.
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The irony is that by the time he gauge in the car shows an issue it's likely been happening for a long time. The gauge will read 90 at any temp from around 77deg and up to over 100. I never saw the gauge move in my car but checked the temps with vcds and saw the temps fluctuating. But the gauge not moving. Mpg wasn't good either as the engine wasn't getting hot. Surprised the master tech relies on the gauge ! :laugh:
The master tech did say they can read the engine temp with their computer probably the next step when it's in next week before any things replaced .just hope it gets sorted and its not something else ,seems strange that the temp only drops under engine breaking .not sure how long it's been happening but hopefully will get sorted .
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Thermostats can fail in a variety of ways, yours is stuck open or not fully closing. If it was the other way round then the symptoms would show up under load and the car would overheat.
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Kahunajb did you get to the bottom of this I'm having same symptoms as you were .
Erratic readings, not dependent on engine charge, it's the temp sensor. Low readings when driving slow or downhill and normal when stopped in traffic, most likely one of the engine stats.
One of?! Blimey.
Pretty sure mine need doing. MPG is woeful and the performance is shat off boost. Time to get my hands dirty!
Engines with manual gearbox have 2 stats. Engines with DSG pre-2008 (or 2007, I'm not sure) have 3 stats and from 2008 (or 2007) have 2.
Mine has 2 stats and the DSG stat was malfunctioning. I had the 2 stats and 3 temp sensors replaced during the mechanical overall. :smiley:
Cheers mate. I'll get the bits in and save that job for when I do a manual decoke. The main stat on the engine block looks far more accessible with the intake out of the equation! Where is the other stat? Mine's a manual. Cheers.
I guess I was induced in error by this topic: http://www.mk5golfgti.co.uk/forum/index.php/topic,78341.0.html (http://www.mk5golfgti.co.uk/forum/index.php/topic,78341.0.html).
Yours only has one. DIY: http://www.mk5golfgti.co.uk/forum/index.php?topic=93576.0 (http://www.mk5golfgti.co.uk/forum/index.php?topic=93576.0).
:happy2:
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Picked the car up from dealers today .
The master tech diagnosed with temp reading in mvbs, thermostat opening too early . Main stats been replaced under warranty :happy2:
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Apologies for resurrecting an old thread but seems pointless creating another as I’m experiencing similar issues and think the thermostat could be at fault.
On my commute to work which starts off with 30mins of town driving including spots of heavy traffic and then 30mins of A roads I’ve noticed that the temperature fluctuates from 90°C to 80°C. The drop in temp seems to occur when I reach the A roads. I did a bit of reading on here and decided to monitor the coolant temp via the hidden menu as mentioned...
After about 16 mins (3 miles) the needle on the cluster had reached 90°C with the climate display showing 72°C which then increased to 80°C after around 25 mins.
Finally reached the bypass with free flowing traffic and as before the needle on the cluster dropped to 80°C (68°C on the climate display). Hit some traffic at the end of the bypass and saw the temperature slowly rise back up to 90°C on the cluster (75°C on the climate display but imagine it would have gone higher the longer I stayed there.) Set off again and the temp continued to rise and fall dependent on traffic.
So in summary, when idling in traffic or slow moving round town the temperature reaches 90°C (82°C on the climate display was the highest reading) but can drop to 80°C (68°C lowest on climate display)
From reading up I think I can rule out the coolant temp sensor and this means the main thermostat is stuck open and needs replacing? This could also explain the poor fuel economy I’ve been getting recently.
Car is a DSG Edition 30, I’m aware that it has 2 other inline thermostats - am I correct in thinking that if one of those was faulty it'd take longer to get to temp as opposed to causing it to rise and fall?
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I haven't gone back over the posts here, but 10 degrees sounds to me to be within a reasonable variance, and down to traffic conditions - free flowing traffic allowing the radiator to do it's job, in cooling, and the thermostat/s kicking in and out with town traffic, and cooling fan doing the job to cool things off in town.......? lots of folk more knowledgeable than me though.
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Stat needs replacing. 68 Degrees C is 20-25 degrees lower than it should be. It should get to around 90-92 and vary maybe 5 degrees either side
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That’s what I though, cheers. I’ll get it booked into the garage as it looks a pain of a job
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Stat needs replacing. 68 Degrees C is 20-25 degrees lower than it should be. It should get to around 90-92 and vary maybe 5 degrees either side
Had the main thermostat replaced and picked the car up this morning. Drove to work, the needle reached 90° and stayed there so I think it’s solved the problem.
One thing though - the figures on the climate display are higher than they were before but never reached 90°. Highest was 87° and lowest was 83° whilst the needle stayed at 90°.
I’m guessing this is within tolerance and I should only be concerned if the needle actually drops?
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Stat needs replacing. 68 Degrees C is 20-25 degrees lower than it should be. It should get to around 90-92 and vary maybe 5 degrees either side
Had the main thermostat replaced and picked the car up this morning. Drove to work, the needle reached 90° and stayed there so I think it’s solved the problem.
One thing though - the figures on the climate display are higher than they were before but never reached 90°. Highest was 87° and lowest was 83° whilst the needle stayed at 90°.
I’m guessing this is within tolerance and I should only be concerned if the needle actually drops?
Yes. :happy2:
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Great, cheers for the reply