thermostat removal

[72panelvan]

A mechanic I know suggested removing the thermostat to help cooling. I guess this would slow the warm up, but would it greatly aid the flow of coolant? Worth trying or not? [/quote]

[Ianbott]

No engine should be run without a thermostat if it was designed with one, running without it will prevent the engine reaching operating temps. If your vehicle is overheating fix the cause rather than going for a quick fix.

[Alex (FTS)]

I did this a few years ago and had no problem what so ever, but if you are thinking of doing this it probably means you cooling system isnt working as efficiantly as it should be so probably worth looking at that and trying to get it to work better or re design. But as a short term solution removing the stat will help a bit.
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www.faltownskateboards.com

[72panelvan]

cheers both! it's only ever really got hot and boiled once, but the fan's kick in on hills and at speed with a lower than stock temp fan switch. I've recently changed the fan mount, raised the van and will lower my rad frame in an attempt to get the exiting side of the rad in better stream of air, from reading other posts and throughts on here I think stagnating hot air exiting is my issue.

The fan mount I had previously was solid plastic so the only way for air to exit was through the holes for the fans, in the vehicle it was designed for (t4) the volume of cold air forced in would have abated this, but I get the feeling with a successful belly mount both sides have to work efficiently.

Surely removing the thermostat would slow warm up rather than prevent the engine from reaching operating temp?

[Joel]

They do more than just help warm up.
Even when a thermostat is fully opened it provides a slight restriction there which is needed.
the coolant will flow through the radiator too fast without one so if you are hell bent on removing it atleast knock the plunger out of the middle and put the housing back in.

My first engine was like that due to headgasket issues which is a common problem, it used to cool right back down to cold after rolling down a decent hill.

But yes slow fan speed on hills isn;t anything to be concerned about.

removing the 'stat is usually a band-aid fix for a wrongly set up cooling system, more often than not the heater loop not hooked up correctly.
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1974 1303 Germanlook Suba-Beetle
Subaru EJ254, BoostR 17", 4 Wheel discs, Topline suspension and A/C

[ElusiveStranger]

[72panelvan]

hi,

heater loop? is that scooby specific issue? i'm running an aaz and can't see how it's any different to how vw installed in the golf?

I ended up doing a bit of reading after originally posing the question and quickly came accross what joel suggested, removing the thermostat can cause the coolant to flow so quickly the heat won't dissipate! silly question in hindsight but thought i'd ask!

I was rushing to get the van back on the road for a festival last week after making a raft of changes, raising the suspension, modifying the scoop, fitting larger wheels and fixing some exisiting little issues. I also thought i'd try a lower temp thermostat as it's only a few quid and worth a shot as I didn't like the fact that my low temp fan switch was 85 degs and the stock thermostat was 87 degs! I found an 80 deg one (there's a neuspeed one for 82 degs which supposedly a standard vw one just in a different box and more money, but couldn't find the original part number) which was part number QTH329k, same dimensions, same stat just lower temp, fitted it and combined with the other changes it's really helped stabilise the temps. Fest was outside winchester and there's quite a few big hills from ringwood onwards and along the M3, but it was excellent, best it's ever driven! very satisfying!

[Joel]

Nice work.

Sorry I assumed it was a subi conversion, yes its a subi specific issue.
In Subarus they do it a bit different and have the 'stat blocking the flow on the return from the radiator rather than the supply too the radiator.
They use the heatercore flow to control the thermostat so its critical to have it hooked up so not an issue in your case.
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1974 1303 Germanlook Suba-Beetle
Subaru EJ254, BoostR 17", 4 Wheel discs, Topline suspension and A/C

[splitbus67]

Joel

Could you elaborate on the head gasket issue you had, what were the symptoms?

My van was running fine until two weeks ago when we rounded a bend in the road to find it flooded with about 5 inches of water, unfortunately the water was was about the height of the scoop which was ripped off punching two holes in the radiator, it wasn't until 5 miles later when the gauge alarmed when the temperature exceeded 100c that I realised there was a problem.

With the new radiator fitted its running hotter than it did and the fan's keep coming on when I'm driving, i've also noticed that the fans don't run if get above 90c, its hit 100c a couple of times causing me too stop and wait for it to cool down, coasting down hill cool the engine.

Phil

[Joel]

Hi Phil,

My headgaskets were on the edge from day 1.

Out on the open road my it ran nice and cool but around town in slow traffic the temp would creep up and the fan initially cooled it down but over the coarse of a few weeks it struggled more and more to cool down when just idling, with higher rpm it cooled ok but eventually it just couldnt keep it cool.
I found the milkshake under my oil cap and when I pulled the heads off it had been totally eaten out inside by electrolysis.

It wouldn;t be your problem but it does sound like your head gasket could be suspect, especially if it got run hot when your radiator punctured.
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1974 1303 Germanlook Suba-Beetle
Subaru EJ254, BoostR 17", 4 Wheel discs, Topline suspension and A/C