ocphilip: Hey friends, I just got a volkswagen golf 4 which was imported from Holland, and it came with a thermostat, between the radiator and engine to pre-heat in d radiator water or so. When I'm driving, I notice that it rises the engine temperature till about half of the temperature gauge, then stops there. The engine temperature hardly changes from that point, thus showing that the thermostat works. But all the mechanics I meet are strongly advicing me to remove it. Pls I need your advice

Siena: Your thermostat's working just fine. The optimum operating temperature is between 86 - 100 degrees celsius. With the gauge in the middle, it's reading approximately 90 degrees celsius, which is normal.

Do NOT allow your "mechanic" to remove the thermostat!! If he does, your engine will over-cool. So it may read close to normal when stuck in slow-moving traffic, however on the highway at constant speeds, the needle will drop to the cold zone. This is dangerous for your engine. Besides the higher than normal fuel consumption, cold oil does not provide adequate lubrication when below 80 degrees.

Cold oil will form sludge, which is a condition whereby condensation mixes with your oil, and dilutes it. Add the excessive fuel a cold engine won't burn, and you have a lethal cocktail in your oil pan. Why do you think oil pump failure is rife in Nigeria? Gear damage. Typically, an engine requires 100 psi of oil pressure for every 1,000 rpm. So at 6,000 rpm, 600 psi of oil pressure is required. If your oil pressure drops at high rpm, the first point of failure occurs furthest from the oil pump - the cylinder head. Camshaft/s will seize, and the timing belt will get torn off. If chain-driven, the effects are even worse, the chain may break, or the sprockets will shear teeth.

Worse case scenario, your crank journals and conrod bearings will get starved of oil, resulting in engine knock, in some cases the knock is severe enough to throw a rod through the engine block.

Remove your thermostat at your own peril.

ken4jj: @ Siena and Ikenna,

For those of us who have had thier thermostat removed and some construction already done, what should we do? The only time i get my temp guage at half or close to half is only if i drive with AC on a sunny weather. Without AC it neva gets there.

cretin: at ikenna/siena...any quick fix or fix at alll for a semi sludged engine?...normally run dino oil, but learnt on some forums that running synthetic oil will cleanse the engine after a while...switched to mobil1 , had improved mpg but my oil pressure lamp flickers sometimes now

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Siena, this is the thermostat thread i referred to in another topic. My post is about 4 posts above this.
Ikenna, please you can also contribute.

Nissan primera 97/98 model, 1.6litre engine.
-Can I replace the thermostat myself?
-What does it look like?
-Where is it located? There's one iron stuff with two wires (not connected) directly on the engine block. I'm suspecting that's it but not sure.

I've tried google, no luck. Decided to try you guys here before heading to the mechanic.
Thanks.

Find Out!:
Thanks a lot boss. i'll look at the engine and revert back here if i have any more questions

But what's the significance of the that stuff with two wires? do they have to be connected to something for the thermostat to work?

Siena:

I have no idea what the component with two wires on your engine is, unless you can snap a picture, and post it here. The thermostat is purely mechanical, and does not rely on any electronics to make it work.

#JusticeforAluu4

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Alrite. i'll snap a pic and post here tomorrow morning. But surely, there must be something that'll connect the thermostat to the fans right? Hopefully tomorrow morning, i'll spend some time under the hood.

The first pic you posted (the golden colored stuff inside what looks like springs), is that the thermostat proper?

miccodb: @siena n ikenna, all your points hold valid for as long as the weather conditions specified for the operation is fine. Demerits of removing thermostats cannot b overemphasized and you too can't agree less that weather conditions r drastically changing. Temperate regions r getting unbearably hotter and if ‎​U̶̲̥̅̊'ll agree this is being catered for more by more recent models of vehicles. Removing the thermostat from a 2010 avensis will definitely be as detrimental as ikenna and sienna explained but I can confidently tell ‎​U̶̲̥̅̊ otherwise for a 92 mazda. When these older cars were made temperature specifications hadnot soared and manufacturers didn't cater for temperate regions adequately. Manufactures of cars in 199e didn't envisage maiduguri would get this hot!!! What kind of temperature regulation can a mazda 92 on full load of both transmission and aircon offer to such temperature? Combustion alone causes a lot of heating hence requirement of cooling system. My brodas I've analysed this thermostat thing for years n researched it n my conclusion is let us know the exact car n model before ‎​U̶̲̥̅̊ try to remove thermostat and there must be an underlying symptom or issue that ‎​U̶̲̥̅̊ feel thermostat removal will resolve. These theories we all know attimes don't pan out exactly that way in practical. Removing your thermostats just means ‎​U̶̲̥̅̊ have said to your engine don't restrict the flow of cool water around my cylinder and that's if thers any cool water at all due to the climate and d cooling efficiency of the system. The theories by siena and ikenna hold perfectly for ideal cars and systems. After all we know d ideal gas equation isn't for all gases but only ideal gases n likewise siena's implications. This is my bit.

miccodb: @ sienna, removing your thermostat doesn't make it run just above freezing point cos it aint possible in nigeria. Combustion temperatures alone will take it to abot 50 degrees before we start to talk about ambient temp. No doubt sienna ambient temp plays a lot n hence d original design of thermostat. I believe d original design of thermostats were for the actic regions where temperatures dip so low to even freeze d liquid hence thermostats would shut completely until the coolant around the cylinders reached optimum operating temperatures but wen reverse I'd the case the thermostatwould remain virtually open all d tym.
@ ikenna pls bring ur 505 to lagos leave VI by 5pm and head to egdeda or iyanapaja if ur engine doesn't overheat den we can have dis argument again. Traffic pass traffic n btw it isn't wen ‎​U̶̲̥̅̊ start running ur engine dat overheat start but idling for over 3hrs with aggressive driving and soaring temp oga ur 505 will overheat on AC. I've also tested thermostats in boiling water; the technology is quite simple but that's not the optimim technology obtaiable for all regions. People tweak cars for various reasons!

miccodb: @ sienna, removing your thermostat doesn't make it run just above freezing point cos it aint possible in nigeria. Combustion temperatures alone will take it to abot 50 degrees before we start to talk about ambient temp. No doubt sienna ambient temp plays a lot n hence d original design of thermostat. I believe d original design of thermostats were for the actic regions where temperatures dip so low to even freeze d liquid hence thermostats would shut completely until the coolant around the cylinders reached optimum operating temperatures but wen reverse I'd the case the thermostatwould remain virtually open all d tym.

Siena:

Yep, the colored photograph depicts the thermostat.

Nothing connects the thermostat to the fan. The thermostat controls coolant flow through the block and radiator.

#JusticeforAluu4

Siena: ^^^ That looks like the thermo switch, that switches on the fan, when the pre-set temperature is reached.

Thermostats are dirt cheap - I've just replaced the one in my Audi S8 (4,2 V8) engine, and it cost me £6,20. I would advice you buy a brand new one, and a new thermo switch too.

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kk. So the thermostat can be accessed by loosening those nuts right?

This is the other stuff i told you about (with two unconnected wires) that i felt was the thermostat earlier.

Mech said it has to do with the catalyst (catalytic converter) on the exhaust. He also said the catalyst has likely ''burnt out'' being an ''old car'' (possible??), and that may account for the increased fuel consumption. I'm aware of the relationship btwn fuel consumption & catalytic converter. But then,

1) i believe if a car's catalytic converter is absent, the engine sound will be rough especially on acceleration. The primera's engine is relatively smooth at idle n acceleration, so i feel its still dere. Is dere a way to actually detect its presence (as in if its still working)?

2)even if it isn't i doubt if i'll be able to get a replacement coz that stuff is one expensive vehicle part here. For the average car, based on my observations and enquiries from mechanics and users, u r looking at between N30k - 40k for a catalytic converter (popularly referred to as catalyst). How does the price compare in the UK?


*hope i'm not derailing thread.*

When the thermostat - fan connection has been put back to normal, i'll be sure to come back here with my observations.

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B0oss, sorry for replyin this late. had a busy weekend. so, i think i've been able to identify the location of the thermostat based on the diagram you gave me. i had cause to visit the car's mechanic (fairly trusted) for servicing (changing of oil n oi filter) later that day, so i told him of my intention to have the thermostat working again. naturally he initially said its not necessary, and proceeded to 'educate' me (saying most of what miccodb has just said here). I told him, you kno what, lets try it first, if it overheats (which i'm sure it wouldnt), then i'll consider a reversal back to the current state. but due to time, we've agreed on:

-we fix a date, i take d car to him, stay with him (as always), he checks if the thermostat is still there and working, we arrange the connections back so it works with the fan. if not working / not there at all, we check for the part number and purchase another (can anyone give me an idea how much it costs? Ikenna?).

even he was not too sure initially where it's located, but i pointed it out to him. this is it right?