Engine over heating on AC, minor tweek, DONE

[capsat]

:PSometime back in April - May 2009https://www.pakwheels.com/forums/engine-transmission-powertrain/101759-ee-90-heat-up I requested members to help me with the occasional overheating problem of my daily ride EE90 Auto -It was temporarily fixed after I got the Aircon compressor changed, 3000 km later the problem resurfaced, and I was on & off travelling and paid very less attention. Because My Prado was drowned in rains and it was in TOTAL DONE electronically.

this year June i made up my mind and got the EE90 over hauled. Got major stuff carried in from Dubai & Singapore, -

75 KM done and over heating on the aircon problem showed up, It took day lights outta me and my mechanic, 1. went to aircon shop he checked Thumbs Up, 2. Got the Silencer replaced from front to rear, 3. replaced the radiator - 300 KM done and temp shot up when aircon switched-on, was consistent.

spoke to a friend exporting right hand drive cars from Japan worldwide and explained him the problem, on & off he was chasing some former Toyota guys he knew off - 3 weeks (1900 KM done without aircon) later he called n asked for "CHANGE THE Main engine Pulley Set" -

Locally tried to source but was not convinced of available stuff punched rivetted sliped bolts etc, asked a friend to source it from sharjah - he got me 2 genuine from scarp yard, (2300KM done without aircon) - replaced the Pulley. and WOW, Problem done resolved, - Radiator returned, to the radiator wala for Rs. 500 less. back on the original one. Now its 5700 KM and 2 trips to Quetta, and often to Mirpur Khas temp with aircon needle stays at past 40 min. (consider your clock arm at 40 min).

The pulley we removed from the engine was OK apparently however on close bright light and magnified glass inspection it was revelaed that the rubber bushing over which the outter pulley is screwed. It torques the aircon compressor, was badly cracked. The slip happening between main pulley & aircon pulley happens at high speeds which does not give enough torque to compressor, and WAS causing over heating -

wow, It is done solved now - Alhamdo Lillah -
here is the image with of what am talking about again image is sourced from Pakwheels - " https://www.pakwheels.com/forums/engine-transmission-powertrain/36740-engine-swap-2e-l-5a-fe-finally-done"

[Racerf1]

WoW, what a story and what effort! I have to tell you no one could have diagonsed that fault so minute and magnified, wow! Good write up!

[Xulfiqar]

that cracked bushing slows down the water pump and alternator too, happens alot in Mitsubishi and BMW engines too (BMWs just die because the crank sensor signal is generated from that pulley)

[hash4u]

learnt something really different from this thread
i have seen alot of threads of car heating with AC, but no one ever came with such fix!

[capsat]

[I]@other fellow members, yes it is a new 'fault' even my mechanic with over 40 years of experience was head-over-heals when HEAT-UP occur at 75 km of an over-hauled engine.

@Xulfiqar, thanks for info.

am sure many others will benefit and know ONE More possible reason of engine over heat [/I]

[whiteangel]

That's quite a story!

Glad to see that your problem is resolved

[Porsche_Maker]

Wow, what a diagnosis your friend did for you, amazing i got new thign from this thread but i think its seldom a car have this problem as usual Heatup is due to normal circumstances of Cooling Items of Engine.

[raja_shahbaz]

WOW never thought that this thing can cause a heating issue.... thanks for sharing your experience with us....

[argtr65]

This type of pulley is called harmonic balancer ,and it is connected to the front of the engine crankshaft to reduce the vibration.The harmonic balancer takes out torsional flex in the crankshaft, so that auxillary items driven by the crankshaft front pulley are not accellerated/decellerated rapidly in line with firing pulse and natural harmonic speed variations in the crank. Just like a tuning fork if a cylinder fires it accelerates the crank pin for that cylinder and leads the other parts of the crankshaft slightly. Those parts then speed up and then the crankpin is slowing down. This vibration will be rpm dependent until the crankshaft reaches its natural harmonic frequency. Once it reaches this speed the crankshaft can be excited into greater oscillation than would normally occur. The harmonic balancer takes the crankshaft natural resonant frequency outside of this range.

[raging_ravin]

excellent fix. i was thinking of something else but this is very unusual. was routed to this page via some other page but this is a worthy read.

[homeboy]

After 9 years I think I am having the same issue.

[omersiddiqui5482]

@capsat sir, and @Xulfiqar informative as always....

Had this same issue last year with my father's lancer 91. The main pulley slipped, rubber bushings damaged and the car was heating up and not charging the battery. Saw the pulley is not moving at the same RPM as the engine. Had to change it from a scrapyard engine.