Running Cold

[Sherwy]

Evening all,

I recently I noticed the temp wasn't coming up on the mrs mkiv. 1.6 5 speed. After driving for half an hour it was still on the bottom mark, ambient temp was about 20. Shortly after this it shot up to halfway which is where it normally sits. After another ten minutes or so I noticed it was back down on cold again. This has been happening consistently for a week now. It runs pretty rough when it starts in the morning. I've also noticed that the fans seem to be staying on for a while after you turn the ignition off. It has never done that, not even on really hot days. The engine bay seems remarkably cool even after a long run. Both fans appear to be working, feels like low speed but I can't be sure. Any ideas?

Cheers,

Sherwy.

[Jmac]

pm sent, to summarise for the masses itll be the electronic thermostat, it keeps the fan on and will be broken inside its housing. Common as .
Cheers
Jmac

[ben_marrett]

pm sent, to summarise for the masses itll be the electronic thermostat, it keeps the fan on and will be broken inside its housing. Common as .
Cheers
Jmac

Tried to send you a PM Jmac but your inbox is full... can you please PM me the part that needs replacing??

Is it this- Volkswagen Golf IV 1.8T > Engine > Cooling > Temperature Sensor > ES#2535452 Coolant Temperature Sensor With O-Ring & Clip - 059919501AKTU

Ben

[Sherwy]

Hey Ben,

I doubt that is the correct part judging purely on price.... JMAC told me the part is $195 genuine. He keeps pretty close eye on this forum so I'm sure he'll get back to you soon. In any case I'm in touch with him about getting it fitted to my misses car so I'll let him know about your post.

Cheers,

Sherwy.

[Jmac]

Tried to send you a PM Jmac but your inbox is full... can you please PM me the part that needs replacing??

Is it this- Volkswagen Golf IV 1.8T > Engine > Cooling > Temperature Sensor > ES#2535452 Coolant Temperature Sensor With O-Ring & Clip - 059919501AKTU

Ben

No thats not it mate, the housings differ on the 1.6 some have a conventional thermostat and others have the electronic thermo. The one in question is a newer one with a BFQ motor, some of the early AKL and AEH motors have normal stats, but all use the coolant sensor you have in you link. As the BFQ motor has the electric one it throws the fans on full when it plays up and the engine runs really cool. What is your doing and what engine do you have?? by the way ill clean out my inbox tonight
Cheers
Jmac

[ben_marrett]

Hey JMAC,

Thought id post here so other have access to the info.

Car:MK4 1.8NA(AGN)

The problem is it struggles to get hot... if I leave it idle it gets hot but when driving in this melbourne weather the temp sits at about 1/4 and sometimes goes down to near zero. I have a new thermostat and will replace the current but want to make sure i replace anything else in the cooling system at the same time.

Cheers,

Ben

[marquee]

Mine is exactly as described also. Just different engine. 2.0 apk

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[Jmac]

No harm changing your stat, like i mention above some of the housings are different, and especially the APK one like above. Depending what 1.6 you have it could just be the sensor in your link, but if a BFQ motor itll likely be the elec thermostat which comes with the sensor also so kills 2 birds with one stone.
Cheers
Jmac

[ben_marrett]

No harm changing your stat, like i mention above some of the housings are different, and especially the APK one like above. Depending what 1.6 you have it could just be the sensor in your link, but if a BFQ motor itll likely be the elec thermostat which comes with the sensor also so kills 2 birds with one stone.
Cheers
Jmac

No worries... will change the thermostat tomorrow and see the result.... if I still have troubles i will order the other sensor. Will post back results

Ben (1.8 AGN)

[marquee]

So if I change my thermostat it should be fine

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[Jmac]

So if I change my thermostat it should be fine

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Totally no harm in doing so but i would recommend for your APK change the sensor too, like i say this engine is totally different regarding the stat as the OP. Your sensor might still be the problematic black one anyway, superseded with the green type. Fit both mate i reckon, for such a small item it can cause so much grief. Especially when it causes over fuelling, bore wash, over rich, bad starts etc. Its almost an item you would change every service if not every second. Back in the day the Transporter T4 service kit had a new temp sensor, this was in the Uk before any one gets confused


Cheers
Jmac

[marquee]

Changed and still the same problem. Must be the thermostat

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