Am thinking about lowering my cars normal operating temp .engine is currently running fine as per manufacturers specs but have thru research discovered alot of blown headgaskets with this particular engine so am thinking of lowering the working engine temp by changing the thermostat ,temp sensor and fan relay.fitting a second fan .really want to lower the operating temp by 15-20 Centigrade as my research leads me to believe these engines are prone to cooking.and I feelmaking such alterations will decrease thechances of a major occurring.engine is high compression multivalve all alloy (block and heads) and too me it seems the normal working temp is too high even though its as specified by manufacturer (manufacturer has even attempted to rectify by recommending aradiator additive as a solution and I dont see this as a reliable solution rather i view it as a quick fix).any ideas on lowering the working temp.
intrade,
Jun 21, 9:57pm
what engine! if it is not a old diesel or old carburretor petrol powerd engine then you dont want to mess with the temp especially not 15 degrees.
intrade,
Jun 21, 10:14pm
newer eingine with computer you will need a full ecu remap. Because the ecu is injecting more fuel for coldstart till it reached operation temperature by the sensore mesuring coolant. lowering the temp means for example it will think engine is cold and keep it in rich mode. chewing thru your fuel like hell and make way to much emission etc. heaps of problems.
smac,
Jun 21, 10:16pm
What temperatures are we talking about here! If they are 'prone to cooking' due to design or whatever, that usually means they don't cope well with something going wrong - so radiator gets clogged, and instead of running gradually hotter it breaks. But if it's in good nick and has been running ok I wouldn't see why it would just spontaneously die on you.
Oil needs to get hot enough to boil off water etc. problems will be caused by oil getting sludgy too soon if it's not hot enough (along with impacts on fuel economy, head fouling etc). Not saying what you're suggesting isn't the way to go, just saying you'd really really want to do all your homework first, and preferably only copy what somebody has already successfully done!
phalanax,
Jun 21, 10:46pm
The engines a high output all alloy injected multicam small cube v8 just looking at it first thing that strikes me is the radiators sitting too low.as for affecting the presets in the comps mixtures i dont think 10 or 15 degrees will interfere mixturewise as this engine is designed to run hot (thats the problem .lol)id rather lower the temp a little. than have to do a headjob (alloy block would mean instant crossthreading extracting headbolts)Im thinking of fitting chev thermos and switching gear for the fans and raising the radiator an inch .engine has some ks so i dont think it will affect operations clearance wise.Im doing it .data ive looked at tells me the heads are getting too hot.warping or melting.good point about the oilwill keep an eye on it .maybe less temp change is better .will aim for 10 degrees.currently motor just seems to me to be a tad too hot even though temp gauge is normal.almost smell the oil burn
smac,
Jun 21, 10:49pm
Like I said.what temperatures are we talking about!
As intrade says, the fact that this thing is designed to run hot WILL mean the mixture/efficiency will be impacted (assuming computer etc).
happylad3,
Jun 21, 11:10pm
To me, sounds like a 1uz/2uz Toyota! If it's running slightly hot, why not just do a full coolant and thermostat change! And get the rad cleaned and flushed while your at it! Make sure the fan turns on and off properly and that the waterpump is working properly! Messing around with the operating temps will change all of the fuel mixtures etc.
bigfatmat1,
Jun 22, 12:53am
Why would you change the temp sensor and fan relay. You don't want to be messing with a injected engines operating temp.Changing the theromostat will not change the engine temp either. just take longer to get to operating temp. The temp sensor is a resistance reading the computer takes to calculate things. more than likely the computer will switch ya fans on as well the relay is simply a relay. Dont mess with what you dont understand there is good advise above.
johnf_456,
Jun 22, 1:26am
I agree, get the cooling in top nick and if you wanted maybe a custom radiator op. That is bigger but yeah as above, do not change the running temperature.
pge,
Jun 22, 1:27am
I would suggest a larger, maybe three-core radiator (I once used a Wolseley 6/100), and the extra capacity was an engine-saver. The coolant has more time to release it's heat, and goes back into the block much cooler.It also has a slower circulation-rate, and can therefore remove more heat at a more stable rate.
I would also suggest -- check your thermostat.Is it a 92Degree one! An 88Deg. will probably achieve what you want.
321mat,
Jun 22, 2:09am
If it is prone to cracking heads, I would suggest that may be something to do with poor oil (and water) gallery castings than anything else.
kwkbrk,
Jun 22, 4:39am
Other substantial risk of running too cold is bore wash. ECU puts more fuel in than can be used, which ends up running down the cylinder walls removing the piston lubrication, ie oil. You will end up with worse problems than a blown headgasket ! I`ve recently put a hotter thermostat in my V8 Merc to raise the running temp as I suspected it may have been a bit too low at 80C .
dent,
Jun 22, 6:36am
Would be good to know what engine and what temperatures we are talking about.
dansue,
Jun 22, 7:44am
Heres the answer; 385384975
doug207,
Jun 22, 1:03pm
What about the tolerances within the engine.Usually an engine is designed to work best at its full operating temperature. Must be a British motor of some sort.
strobo,
Jul 14, 2:18pm
The temperature of the coolant can sometimes reach(121 to 135 degreesC). Even with ethylene glycol added, these temperatures would boil the coolant, so something additional must be done to raise its boiling point.
The cooling system uses pressure to raise the boiling point of the coolant. Just as the boiling temperature of water is higher in a pressure cooker, the boiling temperature of coolant is higher if you pressurize the system. Most cars have a pressure limit of 14 to 15 pounds per square inch (psi), which raises the boiling point another(25 C) so the coolant can withstand the high temperatures. If ya mess with thermal efficianciesoutsidethe factory setof parameters expect things like , premature scuffing , aspetrol burnseffectively better at a higher temperature , what you suggest doing isnt exactly a good idea ,especially in a high speedjap enginewhich is specifically designed to run at a certain temp., The cooler it runs the more fuel is wasted /decreased performance, if an engine is cooking/blowing head gaskets etc their is agood reason for thathappening , maybe an air lockin system ,Incorrect engine timing due to worn cam belt or timing chain /gears,etc
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