Driving without thermostat?

[Debbie.gsd]

Hi!
while driving along the other day I heard the fan kick in, and when I looked at the temp guage, it was sky high, and I thought oh oh! been here before, on my last Surf, and the guage didn't warn me till the damage was done, a knackered rad and cracked head. Anyway, pulled over to check, and there was no steam, but lots of water pouring out from somewhere, which could have been the overflow from the expansion tank, which was bone dry and so was the radiator, yet the radiator was stone cold, and I had only been driving for about 10mins. Called my mechanic and he checked a few things, then took the thermostat out, and ran it without, and it was much better, the rad and hoses heated up and no pressure build up in the hose. He suggested I run it without to see if it has cured the overheating, which, touch wood, seems ok. He said he will order and fit a new one for me, but that will be next week. What I'm wondering is, how safe is it to drive without the stat in? I have got to go to a dog show tomorrow which is about a two hour journey, and I'm a bit worried about it!
any oppinions or advice please?

[Silversurfer]

driving without thermostat

From experience it is OK to drive without a thermostat. All it basically does is to restrict the flow of coolant through the radiator until the water in the block has warmed up sufficiantly to open the thermostat and allow full flow. This is solely to allow the engine to warm up quickly. You will use a little more fuel, as the engine will be cooler for longer, the heater will take longer to warm up and if your Surf is an Auto the gearbox will be unable to change up to top/overdrive until the correct temperature is reached. If it is only for a couple of weeks there should be no problems but long term it is better to have a working thermostat for the above reasons.
You can get different tempreture range thermostats for most vehicles so you can fit the one which suits your driving conditions best. ie. a cooler opening tempreture will suit hot ambiant conditions as it will open sooner and vice/versa if you live in a cold climate.

Silversurfer

[RMS_CLK]

Mine done exactly the same thing just a couple of days after i got it. Ive been driving without the thermostat since and I have no intention of replacing it. It takes no time to heat up even with it out.

[marky]

WARNING if you have just bought your 2.4 surf off a Dealer get them to pressure test it.

[Debbie.gsd]

Hi, thanks for your replies! Feel a lot better about driving it to the show tomorrow! I bought this Surf from a dealer back in April last year. It's been driving ok without the thermostat, but no great distance, just concerned about it overheating while on motorway.

[TOYMOTA]

Just something to bear in mind you will be ok running with out a state while your cruising down the motorway,but if you get caught up in any jams or very slow moving traffic which these days is very likely the only thing you can rely on to cool your motor down is your fans which will have to work over time as you have no cool water left in your system!

[Maverick]

I believe that I read the other day that the stat also resticts the water flow slightly causing it to pass through the radiator slower giving the radiator more time to exchange the heat. Personally I changed my stat when it went wrong, as I assumed it was there for a reason, and I like a warm engine within 1/2 mile.

Oh when my stat went wrong it just spat all my coolent out the expansion tank similar to how you described it.

[Debbie.gsd]

Hi,
I'm happy to say I got to the show and back without a hitch! it drove well and luckily it was a straight run without any traffic jams. Hopefully should be getting new stat next week and problem sorted, but I had no problems driving without it, apart from heaters taking ages to warm up!!
cheers everyone for your replies!

[tonymz]

I have been driving without a stat for over 2 months and no problems so far and that includes slow traffic. The engine heats up quite fast as the temp here is around 28 deg celsius. When in mountain driving the temp usually drops as you go downhill...

[MTpockets]

I would suggest you remove the working part of the stat by cutting the 3 posts holding it all together leaving just the outter edge of the stat. Fit it back into the gasket and bolt it back up. This restricts the flow of the coolant sufficantly and also helps seal the housing. However this is mainly a measure you would take to get the car home and is not considered to be a cure for your problem.
cheers
Les

[Debbie.gsd]

Hi,
that is what the mechanic did on my stat. He cut the working part out by cutting through the metal stems holding it together, then replaced the outer part with seal, back into position. He's fitting a new one for me this week, so it was only for short term, but there hasn't been any problems without it. The mechanic has been brilliant with all the jobs he's had to do lately, he's a mobile mechanic and gets you involved with the job and talks you through what he's doing, which is a great way of learning about the mechanical side of the Surf.

[MTpockets]

When I bought my surf and went to put in a new stat, cap and coolant I noticed mine had the guts cut out of it. I replaced it and it immediatly started to boil....... long story short....... new 3l head and Bobs ya cousins father.
cheers
Les

[Debbie.gsd]

I havn't had the new stat put in yet, but when I do, I hope it's the end of the overheating problems, and not start happening again with new stat ,obviously meaning the problem is elsewhere! I've just had a replacement engine put in, which was a nightmare and took two months, for what should have been a couple of weeks work...but that's another story! but I've only just got my Surf back on the road from having this replacement engine, and don't know what problems come with this engine! Had to swop a lot of my original engine parts over to this one as they were in better condition...what does that tell you! Oh well, time will tell!

[Debbie.gsd]

Just to say new stat was fitted thursday, and everything has been ok since...touch wood! No overheating problems, temp guage where it should be, and staying there! Looks like the problem was the stat and not elsewhere...thank God!

[Debbie.gsd]

still problems losing water!

today problems started again, losing loads of water! had been driving for about 10mins, parked up to go to the shop, came back and water was pouring from underneath the Surf. Lifted the bonnet to check, there was no steam or sign of overheating. There hadn't been any indication of a problem with temp guage before hand. Radiator, hoses etc were hot as should be, not like before when had problem with themostat. I checked the rad and expansion bottle, both were empty! Topped up with what water I had with me, then made my way home. When got home, topped up the rad fully, and bottle half way, then took it around the block to test it and it was fine, no sign of any leaking!?! Yet 10mins before it had been !!!!ing out, all over the supermarket carpark. Any ideas any one? could it be down to an air lock? sometimes hear water gurgling around the heaters when first starting up, but heaters work fine!
p.s. the radiator has not long been recored, and the water was coming from the bottom somewhere, possibly a hose?