Overheating

[wasted years]

My '93 has decided to occasionally spew steam at around 90-95 and when this happens the temp guage rises to 100 and when I stop and release bonnet the temp gauage drops to 80ish after 5-10 mins.

I have spoken to Mod-Wise who think their two stage cooling kit may help with kicking in the fans earlier and faster.

One one occasion the steam issue happened at 90 and the temp guage never rose. Any ideas?

[AluminAl]

Is this in traffic or on the open road ?

I`d say you should check your coolant level an bleed the system,Julies 450 will happily sit at 90/95 without loosing coolant,perhaps your pressure cap could do with closer inspection?

The ModWise two stage kit is a worthwhile update but you really need to know how come it`s just started boiling.

[bigdods]

my 450 doesnt start to spew water until >105 (I know from when my otter switch failed!).

Are the fans coming in at the right temp (around 85ish IIRC). My overheating was caused by the otter working intermittently. New otter was £25 and it was very easy to fit took about 2 minutes. Also bleed the system make sure its full with no airlocks.

The modwise kit is good, but you should really get to the root cause of the overheating rather than just bodge a fix.

Edited by bigdods on Thursday 26th July 12:59

[wasted years]

Thanks guys, this is both moving and sat in traffic.

ETA to say Mod-Wise told me to look at the blue cap - it seems ok though. Should any problems be obvious?

Edited by wasted years on Thursday 26th July 13:13

[Meatball]

I had similar problem with my 450 when i brought it it was reaching 110 degrees....changed the thermostat and otter switch and now it wont go any higher than 88 degrees and my rads in a shocking state.

Brought from the kit from leven

[wasted years]

Thanks there!

[TVR Thomo]

wasted years said:

Thanks guys, this is both moving and sat in traffic.

ETA to say Mod-Wise told me to look at the blue cap - it seems ok though. Should any problems be obvious?

Edited by wasted years on Thursday 26th July 13:13

The cap is pressure regulated and a faulty cap will not be obvious (I don't think). I would replace it anyway as they're only about £8 from your local VW dealer (mark 2 golf i think). Make sure it the right one though i.e take your old one with you, I got caught out with one that looked similar and water shot out of the cap about 2 mins of the engine running!!

Cheers
Neil.

Edited by TVR Thomo on Thursday 26th July 13:46

[spend]

Leven kit & a good flush wont go amiss, a new pressure cap is a worthwhile spare as well If you suspect fan control problems a couple of quid for a fan override switch is always useful as well as enabling you to see the effect of switching fans on at any temps.

Dave

[That Daddy]

Dont mess about with that expansion cap, just change it(Euro car parts or Vw dealer stock em its early mk1/mk2 golf, polo,Audi 80 etc, etc)that cap had a high failure rate in its day, for the cost involved i would just change it,looking at it wont tell you anything,its the valve that goes faulty in the lid,and take advice from the other posts,good luck.

Edited by That Daddy on Thursday 26th July 13:46

[wasted years]

Thanks guys!

[GreenV8S]

Check the water levels, bleed the radiator, check the calibration of the temp sender, have the cooling system pressure tested (or test it yourself using one of Steve Heath's adapters).

[AAAndy]

As the others have said, check that there is no air in the system and maybe also change the otter switch. At the end of the day of the day if the cooling system is working perfectly you should not have any issues. So would look for the issue before putting in a 2 stage cooling kit.

[thenick]

Agreed, flush out the whole lot and replace it with nice new coolant and an uprated otter switch. I had this done when my heads came out a while back and since then my 450 has never once stepped above 80 even in heavy traffic in hot weather on the motorway (this was before the rain set in!). This might have something to do with the decat however as im sure it keeps under bonnet temps down having no cats! - A practical excuse to decat??! The uprated otter switch apparently is from the very late model Chims and brings the fans in at 70 rather than 80 which helps quite a bit too.

[wasted years]

Thanks guys. After all that it was an air bloackage. Bled system and no more issues. Will upgrade to the better otter switch soonest.

[neal1980]

where can you get diffrenet otter switches from then i would like the 70 degree one as well....

Thanks

[spend]

I kept a copy of the intermotor list of switches on
http://tvr3.dspen.com/Otter_Switches.html

It may be out of date, but the lowest switch only came on @85C IIRC, and goes OFF at @70C
I believe you don't really want the engine below 70C BTW. If your switch is in the swirl pot - I got lots of false starts due to hot pulses BTW.

Dave

[David Beer]

Or go fully adjustable otter, that way cant go wrong. Well not quite an otter as it lives outside of the pipe/rad.

[That Daddy]

David Beer said:

Or go fully adjustable otter, that way cant go wrong. Well not quite an otter as it lives outside of the pipe/rad.

I take it like the original Kenlowe fan thermostat David?

[David Beer]

Yeah but 100% reliable ! I have used 100s.

[That Daddy]

David Beer said:

Yeah but 100% reliable ! I have used 100s.