Opinions? Overheated from belt tensioner bearing

**stumps** · 1st April 2016, 01:29 PM

Hi all, In my '97 TDI Disco auto, climbing Gateway Bridge the other night and battery light came on half way up...hmmm I thought...that's not good. About 10 secs later aftermarket temp alarm went off, knew I was in trouble then but in the middle lane just on dark not really a good idea to stop. So backed off and let it 'roll' over the crest and idle/neutral as best I could to roll down and exit off on Kingsford Smith Drv. Found Serpentine belt gone...and coolant bubbling out overflow tank and a trail behind car. There goes another head I thought.

Diagnosis when towed home and culprit was the dreaded tensioner bearing..seized and appeared to have melted belt. (My son heard noise just as we climbed the bridge).
Anyway have now replaced the 'bearing only' trick and new belt, and only had to top up about 1.5 -2 litres of water. Have done about 200 km since and somehow all 'appears' ok?

What do you think? Have I dodged a bullet or will it let go on me sooner or later. Head about 50K old.

ROMAROVER · 1st April 2016, 02:12 PM

Probably dodged a bullet

**Fausto79** · 1st April 2016, 03:21 PM

my car used to get the factory temp gauge climbing everytime i went up a big hill in top gear used to always watch n back off. usually when those temp gauges move its already HOT. never lost water though. doesnt take a lot of lost water for those to do damage. pump is right near the top which isnt the best.

anyway when i changed head and gasket recently i looked at my old head. apart from blockages and corrosion etc. the surface was pretty flat.

chances are you may have weakened parts of the head but not warped it too badly. only way to find out is to take it off and get it tested.

for now i would just keep an eye on it. you could possibly get a CO test to see if any gasses leaking into cooling system. if this checks out ok i would relax a bit but still keep vigilant.

i changed bearing on my tensioner but didnt stop squeak. to be honest from my learning i would replace the whole tensioner rather that just bearing. soon as funds allow i will buy a whole new unit.

CO test and listen and feel for anything after and you may have got away with it. do you have an engine saver? for less than $200 it is a massive investment. i would recommend you get one. that may save your engine if there is a problem.

**Blknight.aus** · 1st April 2016, 04:53 PM

I think youve dodged the bullet.

you stopped adding heat before the cooling system was unable to dissipate it.

**stumps** · 2nd April 2016, 08:40 PM

OK thanks for comments. Here's hoping!
I have an aftermarket temp probe with constant display and light/audible alarm and this is what helped me 'possibly' avoid head damage. I have it set to go berserk at 96oC so backed off and idled it down from then on.

On the tensioner bearing, does anyone know if the 6203 deep groove is the way to go for 'extra thermal clearance'. I put in a standard bearing from Repco, just to see if it would run and all has been good so far. Wondering if I should swap it again with an SKF or other quality brand. Disappointed that a new tensioner that was replaced 50k ago could fail like that. Will be listening out for that alot more from now on.

schuy1 · 2nd April 2016, 09:51 PM

I would only use a reputable brand bearing in a critical area like that. What was the tensioner brand you replaced with? I would only use an SKF bearing or a Dayco tensioner. Looks like you may have escaped a head replacement

Cheers Scott

**stumps** · 3rd April 2016, 02:05 PM

Tensioner is a Dayco unit (new about 50k or 3 years ago). I have checked the pulley alignment and all looks OK. Currently checking out looking at best bearing version of the 6203 for this service if that could make a difference.

**loanrangie** · 3rd April 2016, 02:26 PM

Originally Posted by stumps

Tensioner is a Dayco unit (new about 50k or 3 years ago). I have checked the pulley alignment and all looks OK. Currently checking out looking at best bearing version of the 3203 for this service if that could make a difference.

RHP, SKF.KOYO, NACHI, TIMKEN etc will be fine just steer clear of the chinese bearings, i fitted a 6203 to mine not sure in the difference to the 3203 ?

**stumps** · 3rd April 2016, 02:36 PM

Crikey! Apologies ..yes it is a 6203...that's what I fitted. Not sure why I was writing 3203.

I have corrected previous posts.

**Fausto79** · 4th April 2016, 12:55 PM

just be aware that the temperature sensor may not always save you. you can be losing water and temperature stays low until it's too late. low coolant alarm is still the safest bet. after i changed my head etc. i would not run the car without my coolant alarm. its nice to see the head temp too for other reasons but that may not always save you.

really essential investment. not just my opinion but everyone here as well. as Dave Blknight also mentioned, better to install it on the top of the thermostat housing rather than radiator or expansion tank. as the latter two could still be holding water whilst the head is draining/drained.

i was going to install float switch on my expansion tank and hook it up to my madman but he talked me out of it and i ended up making the extra investment to buy an engine saver.

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Opinions? Overheated from belt tensioner bearing

Thanks for advice and comments.

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