MK5 Golf GTI
All Things Mk5 => Modifications & Technical Area => FAQ's => Topic started by: K1NGY14 on July 31, 2016, 08:11:21 pm
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Hi all,
Sorry to create another thread about this.
Basically I'm having a little issue with my GTI is have a slight hesitation and it's like the car is over fueling under load. My car gets up to temperature well on the dash, it shows a solid 90 but when I check the temps on the a/c dials it doesn't go about 74-76.
Does that sound like my main thermostat has failed and may be causing a hesitation and MPG issue?
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I cant comment for the hesitation issue, but my guess for the car not getting up to the correct temperature would be the main thermostat. Does it not get there at all? If it was an inline thermostat at fault I expect it would get to 90 eventually, but not for a while. If it simply isn't getting to temp i'd say main stat. The gauge itself is usually eager, but eventually the real temperature does catch up with the gauge and both will sit around 90.
If your coolant is only 75 degrees then your engine isn't running how it was designed to run, and MPG will suffer because of it.
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I cant comment for the hesitation issue, but my guess for the car not getting up to the correct temperature would be the main thermostat. Does it not get there at all? If it was an inline thermostat at fault I expect it would get to 90 eventually, but not for a while. If it simply isn't getting to temp i'd say main stat. The gauge itself is usually eager, but eventually the real temperature does catch up with the gauge and both will sit around 90.
If your coolant is only 75 degrees then your engine isn't running how it was designed to run, and MPG will suffer because of it.
Thanks for this mate, I've got myself booked in at Awesome in a few weeks to get it changed.
Hopefully that'll sort the issue :)
Sent from my iPhone using Tapatalk
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No worries pal glad I could help.
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I cant comment for the hesitation issue, but my guess for the car not getting up to the correct temperature would be the main thermostat. Does it not get there at all? If it was an inline thermostat at fault I expect it would get to 90 eventually, but not for a while. If it simply isn't getting to temp i'd say main stat. The gauge itself is usually eager, but eventually the real temperature does catch up with the gauge and both will sit around 90.
If your coolant is only 75 degrees then your engine isn't running how it was designed to run, and MPG will suffer because of it.
Thanks for this mate, I've got myself booked in at Awesome in a few weeks to get it changed.
Hopefully that'll sort the issue :)
@K1NGY14 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=10237) did you get this sorted out? ie was it indeed the main thermostat?
Sent from my iPhone using Tapatalk
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I cant comment for the hesitation issue, but my guess for the car not getting up to the correct temperature would be the main thermostat. Does it not get there at all? If it was an inline thermostat at fault I expect it would get to 90 eventually, but not for a while. If it simply isn't getting to temp i'd say main stat. The gauge itself is usually eager, but eventually the real temperature does catch up with the gauge and both will sit around 90.
If your coolant is only 75 degrees then your engine isn't running how it was designed to run, and MPG will suffer because of it.
Thanks for this mate, I've got myself booked in at Awesome in a few weeks to get it changed.
Hopefully that'll sort the issue :)
@K1NGY14 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=10237) did you get this sorted out? ie was it indeed the main thermostat?
Sent from my iPhone using Tapatalk
Yes it has sorted the issue and my car is now running fine and my MPG has returned back to normal.
Sent from my iPad using Tapatalk
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Good to hear. :happy2:
Hopefully it will do the same for mine when the part arrives and I install it.
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I cant comment for the hesitation issue, but my guess for the car not getting up to the correct temperature would be the main thermostat. Does it not get there at all? If it was an inline thermostat at fault I expect it would get to 90 eventually, but not for a while. If it simply isn't getting to temp i'd say main stat. The gauge itself is usually eager, but eventually the real temperature does catch up with the gauge and both will sit around 90.
If your coolant is only 75 degrees then your engine isn't running how it was designed to run, and MPG will suffer because of it.
Thanks for this mate, I've got myself booked in at Awesome in a few weeks to get it changed.
Hopefully that'll sort the issue :)
@K1NGY14 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=10237) did you get this sorted out? ie was it indeed the main thermostat?
Sent from my iPhone using Tapatalk
Yes it has sorted the issue and my car is now running fine and my MPG has returned back to normal.
Sent from my iPad using Tapatalk
how much was it for the thermostat job?
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I cant comment for the hesitation issue, but my guess for the car not getting up to the correct temperature would be the main thermostat. Does it not get there at all? If it was an inline thermostat at fault I expect it would get to 90 eventually, but not for a while. If it simply isn't getting to temp i'd say main stat. The gauge itself is usually eager, but eventually the real temperature does catch up with the gauge and both will sit around 90.
If your coolant is only 75 degrees then your engine isn't running how it was designed to run, and MPG will suffer because of it.
Thanks for this mate, I've got myself booked in at Awesome in a few weeks to get it changed.
Hopefully that'll sort the issue :)
@K1NGY14 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=10237) did you get this sorted out? ie was it indeed the main thermostat?
Sent from my iPhone using Tapatalk
Yes it has sorted the issue and my car is now running fine and my MPG has returned back to normal.
Sent from my iPad using Tapatalk
how much was it for the thermostat job?
About £130
Sent from my iPhone using Tapatalk
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Mine cost me 4 hours of labour :signLOL:
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I cant comment for the hesitation issue, but my guess for the car not getting up to the correct temperature would be the main thermostat. Does it not get there at all? If it was an inline thermostat at fault I expect it would get to 90 eventually, but not for a while. If it simply isn't getting to temp i'd say main stat. The gauge itself is usually eager, but eventually the real temperature does catch up with the gauge and both will sit around 90.
If your coolant is only 75 degrees then your engine isn't running how it was designed to run, and MPG will suffer because of it.
Thanks for this mate, I've got myself booked in at Awesome in a few weeks to get it changed.
Hopefully that'll sort the issue :)
@K1NGY14 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=10237) did you get this sorted out? ie was it indeed the main thermostat?
Sent from my iPhone using Tapatalk
Yes it has sorted the issue and my car is now running fine and my MPG has returned back to normal.
Sent from my iPad using Tapatalk
how much was it for the thermostat job?
About £130
Sent from my iPhone using Tapatalk
That seems reasonable. is this just the main thermostat change?
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Hi all,
Sorry to create another thread about this.
Basically I'm having a little issue with my GTI is have a slight hesitation and it's like the car is over fueling under load. My car gets up to temperature well on the dash, it shows a solid 90 but when I check the temps on the a/c dials it doesn't go about 74-76.
Does that sound like my main thermostat has failed and may be causing a hesitation and MPG issue?
Sent from my iPhone using Tapatalk
Apologies for digging up an old thread but my symptoms are very similar so didnt think it warranted a new one.
Similar to @K1NGY14 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=10237) my dash gauge shows a solid 90° and doesnt take long to get there. However, Ive taken the car for a drive the last couple of nights and driven slow, hard/fast, on open roads and in traffic and the temp on the Air Con read out sits around 77-82°. Not once have I seen it creep above 82° and I know this is still hotter than @K1NGY14 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=10237) was seeing but is its still too low? What figures do you guys see? Car is a stock ED30 by the way.
Cheers.
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Probably main thermostat stuffed then. Mine used to be slow to get up to temperature on the dash, (about 20 minutes of rush hour commute) and then after changing coolant it wouldn't show above 80°C on the dash, unless I sat in stopped traffic for a few minutes when it would creep towards 90°C and then drop again as soon as I started moving.
All good after putting in a new main thermostat. Up to 90°C on the dash in about 7 minutes now.
Do you plan on changing it yourself?
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Probably main thermostat stuffed then. Mine used to be slow to get up to temperature on the dash, (about 20 minutes of rush hour commute) and then after changing coolant it wouldn't show above 80°C on the dash, unless I sat in stopped traffic for a few minutes when it would creep towards 90°C and then drop again as soon as I started moving.
All good after putting in a new main thermostat. Up to 90°C on the dash in about 7 minutes now.
Do you plan on changing it yourself?
Im not too sure yet, hadnt thought too much about it as really want to confirm if it is causing an issue.
As I say, mine gets to temp on the clocks in no time and stays at a solid 90°, its the 'secret menu' in the AC that shows a true reading of 77-82° and never higher.
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Sorry, re-read your post and symptoms are different to mine. Dunno what mine(standard GTI) sits at on digital gauge anymore as changed to mk6 climatronic unit. Someone here with an ED30 should be able to tell you.
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So I have stock Eddy and the gauge used to do the usual symptoms of a failed main thermostat. Basically never getting to 90 and showing as low as 75 on the dial and even lower in the hidden AC value. By the way that latter value is the block water temp.
Replacing the thermostat fixed all these issues. The guage should rise to 90 within about 5 mins and stay there no matter what if all is well. The hidden AC value should show about 85 to 87 and no lower, if it does the thermostat is sluggish and on its way out. My personal experience of course but gives you an idea of what to look for.