Topic: water tempreture (Read 6644 times)

greenjeepowner · « **on:** March 15, 2007, 08:08:42 AM »

finaly fittered a new sender unit to the wrangler 2.5 too find that she runs at about 105 to 110 when warmed up....is this normal... my cherry 4lt hardley ever strays past 100 unless i'm in real heavy traffic......

Dave69 · « **Reply #1 on:** March 15, 2007, 08:46:37 AM »

105 to 110 sounds a bit high, the temp shoul be just below the 100 except when under load like towing something large up an incline then the temp will rise. try running the engine with the rad cap off to bleed air out.

sounds like you might have an air lock in the system

Mike Pavelin · « **Reply #2 on:** March 17, 2007, 11:58:39 AM »

Flush the cooling system and try again. Also check the viscous fan coupling on the fan is working.

greenjeepowner · « **Reply #3 on:** March 19, 2007, 07:48:07 PM »

have flushed system as suggested (twice now) left running with cap off to allow air to blow out and new antifreeze added....... engine still rises to 105/110 when accelerating but drops back to around 100 when ticking over in traffic... fan also seams to work ok (speeding up as revs increase /slowing on decrease) .any ideas or should i just leave it....

Dave69 · « **Reply #4 on:** March 19, 2007, 11:10:54 PM »

the gauge may be showing those temps but if you can get your hand on the radiator and see if it has any temperature differences across the core when at temp. it should be hot across the top and slightly cooler towards the bottom, if it has cold spots then your rad might have blocked cores reducing the flow

greenjeepowner · « **Reply #5 on:** March 20, 2007, 08:36:19 AM »

rad fine, have noticed exhaust blowing a bit, would this make a difference, just ordered a replacement muffler from quadrotec...(blowing where pipe enters exhaust box from front of veicle)

Dave69 · « **Reply #6 on:** March 22, 2007, 09:23:52 PM »

a blowing exhaust shouldn't have a feect on the engine water temperature, mine had lost the tail pipe and the silencer shell was blowing and no adverse temperature rise.
have you checked the thermostat to see if it is working? after everything else thats the only real answer i can think of

greenjeepowner · « **Reply #7 on:** March 23, 2007, 12:03:42 AM »

full radiator pressure test done last night in workshop, small leak at top of rad, clip busted holding hose to thermaststat cuasing slight leak...replaced with jubilee clip..thermostat working fine. upon running engine up to temp.. thermo readings taken from thermostat 88degrees/ top rad hose 86 degrees /sender unit on rear of engine 107 degrees same as guage... this has only just been replaced......engine pressure tested to also check if head gasket gone...all four plug holes returned between 10 and 20% ... our head techy said this was perfect for an engine with 93000 miles so no blown cylinder head gasket..... guage still running at 110 dropping to 100 in traffic..... still at a loss... our head tech said not to worrie.. but i hate things not working correctly.. my cherry runs at 97/98 all day long only creeps a little over in heavy traffic... wrangler works oposit 110 when driving dropping back to 100 in traffic

Dave69 · « **Reply #8 on:** March 23, 2007, 07:08:31 PM »

thermostat 88 degrees
top rad hose 66 degrees
rear engine sender unit 107 degrees

these dont add up to me, the top hose should be close to the thermostat reading as it is normally a direct feed from the engine. 66 degrees isto be way too low in comparison for this engine since there is no additional cooling before the radiator

??

the top hose should be close to the engine temp, the temperature at the rear of the engine maybe higher as there will be limited air flow and so hotter. the bttom hose should be say 10 degrees or more lower than the top hose due to the cooling affect of the fan, this will obviously change depending on the style of the fan fitted, and the style of driving.

greenjeepowner · « **Reply #9 on:** March 23, 2007, 07:29:46 PM »

my appologies top rad hose 86 degrees... have amended post....

Mike Pavelin · « **Reply #10 on:** March 23, 2007, 08:17:06 PM »

Can you see a lot of gunge in the radiator core tubes through the rad cap hole?

greenjeepowner · « **Reply #11 on:** March 23, 2007, 08:45:14 PM »

no rad real clean have flushed hole system twice know....

Dave69 · « **Reply #12 on:** March 23, 2007, 09:59:43 PM »

youve got a good one there.

basics time, so dont shoot me down for stating the obvious.

engine starts, water then flows around the block getting warmed. the thermostat is closed so reducing the flow to the radiator which is constantly cooled by the rad fan "running at engine speed". When the engine reaches a set temperature the thermostat opens "normally around the 80 degrees" thus allowing full flow of water through the radiator core so reducing the thermal shock to the engine.

with radiator developement the key points for temperatures are recording the top hose as this is the maximun engine water temp then the bottom hose temp is recorded as the water is then cooled by the air passing through the radiator core, the lower reading of the bottom hose is then taken away from the higher top hose temperature to give a temperature drop. this can give the effectivene cooling of the radiator and cooling fan. the bigger the number in the answer the more effective the radiaqtor setup.

with a 50-50 mix of water to glyco which in itself lower the boiling point of water. also the flow will create a pressurised system which has the same effect. this keeps the temperature below the boiling point of water. so with an adequate radiator and fan the temperature will sit around the "90 degrees" a ball park figure but will vary vehicle to vehicle.

the temperature of the engine is also cooled by the lubricating engine oil via a sandwich plate at the base of the oil filter (fitted on a diesel not sure on a petrol). this is quite effective, or the oil flow can be directed to an air to oil cooler (mocal style) to provide cooling as well.

most temperature sensors are positioned near or close to the thermostat on the feed line to the radiator. I am surprised to see one fitted to the back of an engine (please correct). With the figures your quoting i would ignore the temperature gauge and go by the top hose figure. If you could get an actual bottom hose reading of the coolant to compare with the top hose coolant and see what the difference is that would give you some confidence in the engine. What the temperature of the engine is, is not a true concern as this will get hot no matter what you do. As long as you know the top hose sits at 86 degreesC and the bottom hose is say 75 or 78 degreesC you will know the water is being cooled sufficiently. What you could do is measure the oil sump temperature as well. Just put a thermocouple down the "dip stick" and look at the reading when the engine is fully warm. This will be higher than the water, possibly around the 110 degrees or slightly less. this is proportional to the water, meaning if one rises the other does as well. the oil temp should be stable and it just adds a bit of confidence to the water temps. Oil temps over 120 degreesC are not good as the lubricating properties drop to nothing and will result in premature engine wear.

not an answer but a way to get some confidence in your vehicle. maybe a trip to a motorfactors to buy some electric temp sensors and displays just for peace of mind

greenjeepowner · « **Reply #13 on:** March 23, 2007, 10:19:38 PM »

the sender for the temp guage is on top of the head at rear of engine bay.... this was showing 107 same as guage..... water has approx 50/50 mix used nissan coolant already pre mixed ( work there so have a few perks/ including full workshop use after hours) was thinking of fitting an oil cooler plus auxilary oil temp guage....

greggmo · « **Reply #14 on:** March 23, 2007, 10:34:06 PM »

what is the outside condition of the rad? are the fins good and have you pressure washed it through the fins. if there is muck in the fins the rad will not cool properly. you can also do a flow check by taking off top and bottom hose put your hand over the bottom outlet on the rad then fill it with water, take your hand off the outlet and the water should pour out very quickly. if it does not empty quickly the tubes are blocked with scale or radweld if it has been used in the past. if the fins are loose on the tubes in the core the rad will also not cool to its maximum so just check them by putting your fingers on the front of the rad and gently rubbing them if they don't move all is good, if they crumble you need a new rad or re-core.

greenjeepowner · « **Reply #15 on:** March 23, 2007, 11:02:40 PM »

water pours out of both hoses..... rad is perfect all bar a very small trickle from top this was only present when we pressurisred rad up to 60lb pressure...... high flow aluminium 2 cor rad is on my list though.....when system flushed both times no sign of any sludge or rubbish...

greggmo · « **Reply #16 on:** March 23, 2007, 11:24:11 PM »

so if the flow is ok it must be blocked on the outside through the fins.otherwise it should keep the engine cool. is your heater good?

Bubba · « **Reply #17 on:** March 23, 2007, 11:52:40 PM »

just an odd one is the water pump working properly as i have had a few cases of the impeler dropping off and yet not overheating badly at least not on tick over and short trips i must add never had it on a jeep but as say i have had it happen

greenjeepowner · « **Reply #18 on:** March 23, 2007, 11:55:34 PM »

Quote from: "greggmo"

so if the flow is ok it must be blocked on the outside through the fins.otherwise it should keep the engine cool. is your heater good?

heater can get well hot if on 2/3/4 speed. rad was removed and cleaned,... then replaced . no visible exterior blockage between fins when it was cleaned....

Mike Pavelin · « **Reply #19 on:** March 24, 2007, 08:35:21 AM »

Does it keep the temp down if you keep the heater on flat out?

Dave69 · « **Reply #20 on:** March 24, 2007, 11:04:41 AM »

60psi test pressure thats a bit high for testing normally 2bar max (30psi) or you stand a chance of popping the copper braze core. Ally rads are nice but the coper cores as std are more efficient in heat transfer

greenjeepowner · « **Reply #21 on:** March 24, 2007, 08:06:59 PM »

Quote from: "Mike Pavelin"

Does it keep the temp down if you keep the heater on flat out?

will try sunday....
thanks for your feedback guys

greenjeepowner · « **Reply #22 on:** March 25, 2007, 04:55:06 PM »

Quote from: "Mike Pavelin"

Does it keep the temp down if you keep the heater on flat out?

took jeanie on her furthest journey yet from reading to oxford and back about 70 miles intotal covered , had heater on full blast whole time to oxford, was still reading up to 110 averaging 105/107 had to turn heater down on way back as too hot in cab.....even when i was doing 70 didn't make any difference,, when ticking over in traffic or at lights dropped back to 100.....

Dave69 · « **Reply #23 on:** March 25, 2007, 06:47:35 PM »

Quote from: "greenjeepowner"

Quote from: "Mike Pavelin"
Does it keep the temp down if you keep the heater on flat out?

had heater on full blast whole time to oxford, was still reading up to 110 averaging 105/107 had to turn heater down on way back as too hot in cab.....quote]

that's what windows are for just open them a bit LOL

Author Topic: water tempreture (Read 6644 times)

greenjeepowner

Mike Pavelin

greenjeepowner

greenjeepowner

greenjeepowner

greenjeepowner

Mike Pavelin

greenjeepowner

greenjeepowner

greenjeepowner

greenjeepowner

Mike Pavelin

greenjeepowner

greenjeepowner