VW Overheating

My 1985 Passat runs too hot. It's been getting progressively worse over the last five years. It's not the rad or the theremostat. I think it's the corrosion in the water galleries getting slowly worse restricting the flow. Is there a solution to this other than a new engine? Any help would be appreciated. Thanks

UKD

Reply to
ukdodger via CarKB.com
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Corrosion or scale buildup? Sure it's not the water pump or fan clutch? Water pump impellers can wear off over time.

Reply to
DougW

You know this because ...

Remember, just because you can see water in your radiator, doesn't mean it's plugged. A new radiator is cheap compared to the replacement of a head or motor and, since you're driving an 85, it's entirely possible that's all it is.

Things that can also cause what you describe:

Water Pump Fan Clutch Bad Timing Head Gasket going bad. Transmission overheating (if you've got an auto tranny)

Reply to
Gary L. Burnore

You won't have "corrosion in the water galleries" if you have used the proper coolant mix through the life of the vehicle. How do you know it's not the rad or the thermostat? How do you know that you don't have a bad temperature gauge? When was the last time you changed your accessory drive belts, cleaned your radiator or looked for rat nests under the hood?

To answer your question, there are coolant flush kits, and businesses who perform this service for their clients. I assume that they will be available in the UK. Follow the directions exactly. If your problem is clogged water galleries, it may help.

Cheers,

Earle

Reply to
Earle Horton

If "if" were horses baggers would ride. God Bless America, Bill O|||||||O mailto: snipped-for-privacy@aol.com

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Reply to
L.W. (Bill) Hughes III

Hi Gary. Thanks for reply. Well I've changed the thermostat and cleaned the rad and checked the water pump. It goes round Ok, the impeller isnt damaged and the drive belt doesnt slip. It's the gradual increase in temp over the years that makes me suspect the scale build up. Thanks anyway.

Ukd

Gary L. Burnore wrote:

Reply to
ukdodger via CarKB.com
  1. stop top posting.

You can't really clean the radiator. You'd need to remove it and either have it re-cored or "rodded" which is a term that means remove the ends and stick a rod through each tube. Cheaper to buy a new one.

Scale doesn't just build up in one place, and as others have stated doesn't happen if you're taking care of your vehicle. The things I've mentioned, however, occur no matter what over time.

A tip for your radiator. Take it out and empty it. Plug all the holes but one and fill it. Empty what you just filled into a measurable container. See if the amount it held matches the capacity of the radiator. (Bet it doesn't)

Reply to
Gary L. Burnore

Hi Earle. Well I've always run it on just plain water I dont think the manual asks for anything else. The temp drops if I remove the thermostat completely. I thought of flush kits but the corrosion that I can see looks bloody hard you sure a chemical would remove it. Thanks

Ukd

Earle Hort>> My 1985 Passat runs too hot. It's been getting progressively worse over

Reply to
ukdodger via CarKB.com

If you check the manual you will very likely find that is specifies the coolant both as to mix and standard, and may also specify the use of distilled water.

If removing the thermostat completely brings the temperature down then it would seem more likely to be the thermostat. Does it open fully at the specified temperature?

Reply to
J. Clarke

You need to run it on a 50/50 mix of distilled or otherwise pure water and ethylene glycol coolant with a proper anticorrosion mix as recommended by the vehicle manufacturer. If you don't have that, if you have been putting tap water in there, well what you see is what you get.

Try the flush kit, or bring it to a professional radiator shop. Then find out from VW what type of coolant they want you to put in there, and use that in the future. No tap water. Tap water is bad for automotive coolant systems. Not all tap water is bad, but why take a chance? God, the stuff they have in Albuquerque filled up my electric tea kettle with mineral deposits in three months...

Cheers,

Earle

Reply to
Earle Horton

Thanks Earle. Appreciate your advice.

Reply to
ukdodger via CarKB.com

Reply to
ukdodger via CarKB.com

Hi J. That's what had me fooled first time. So I bought a brand new thermostat. That made no difference so I bought another. Same thing. I put them both in a saucepan of water heated the water up with a thermometer inserted and both opened fully at the approximate correct temperature. I'm about to try testing the rad for how much water it holds. If it's right I cant see any other cause except corrosion in the galleries. Thanks for your help.

Roger

J. Clarke wrote:

Reply to
ukdodger via CarKB.com

Roger, please stop top posting. It's quite annoying.

Reply to
Gary L. Burnore

Sorry not understood. 'Top' posting please explain???

Gary L. Burnore wrote:

Reply to
ukdodger via CarKB.com

Top posting is not only allowed, it is encouraged in rec.autos.makers.jeep+willys. So just shut up about it.

Cheers,

Earle

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Reply to
Earle Horton

Sorry, Earle, it's against usenet rules of etiquette.

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Reply to
XS11E

Reply to
L.W. (Bill) Hughes III

but not as annoying as having an 11 line signature..

Dave Milne, Scotland

Reply to
Dave Milne

Or a mental defective jerk who keeps insisting that everyone else adhere to his imagined Usenet posting standards. Eat it, Burnore.

Cheers,

Earle

Reply to
Earle Horton

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