On one hot afternoon occasion, on heavy traffic. My 2001 Grand Vitara V6 AT temperature gauge needle went up to almost 3/4, aux fan is ok and so is the coolant level on the reservoir tank, but the aircon was getting warm. I turned of the AC still on heavy traffic and after a while,  the temperature gauge went down to its normal level (half). Turned on the AC, and everything was back to normal.


Has anybody experienced this? What seemed to be the problem? I would surely appreciate inputs on how to diagnose this problem/occurrence.

My guess is sticky thermostat.  No direct connection with the AC, it's true, but that could be co-incidental.

Hi IanL

Does this mean the thermostat is shot/broken already? I agree with you on the aspect of the aircon getting warm. Its probably due to the rising temperature of the engine making the compressor work twice harder.

dindo

Hi IanL

Does this mean the thermostat is shot/broken already? I agree with you on the aspect of the aircon getting warm. Its probably due to the rising temperature of the engine making the compressor work twice harder.

dindo

Go take a look under the hood - you're looking for the a/c condensor and the radiator - they're usually at the very front of the engine compartment, and usually the a/c condensor is in front of the radiator.

Now - the air flow is through the condensor and then through the radiator - it's very important that you understand this - because it means that a hot radiator does not have as much impact on the condenser as a hot condensor has on the radiator.

To make a long story short ...

Hot day = more heat energy in the passenger compartment to be removed = higher condensor temperatures.
Heavy traffic = reduced vehicle speed = reduced air flow through the condensor = reduced ability to dissipate the additional heat = hotter air coming off the condensor and onto the radiator.

Eventually the a/c just cannot remove any more heat from the passenger compartment because the condensor cannot get rid of it fast enough and the passenger compartment will start to heat up.

As this is happening - the radiator is being faced with a double whammy in the form of a reduced air flow due to the reduced vehicle speed PLUS the air being at a higher temperature due to the air conditioning load, the radiator cannot dissipate the engine heat fast enough so the engine temperature will start to climb.

Shutting off the a/c removes the additional heat that the condensor is trying to dump into the air, which allows the air reaching the radiator to be "less hot", allowing the radiator to do a better job of dissipating the engine heat.

I couldn't have explained it better!  

I'd like to add that you no longer have perfect heat transfer capability compared to "as new". Radiators and condensers get crapped up w/debris, bugs, dirt and film over time, not to mention INTERNAL coolant passages and surfaces acquire built up corrosion / film too which affect heat transfer.

Are those components CLEAN inside and out?!? Also, listening to the symptoms, I wouldn't jump on the thermostat yet.

Thank you for all the insights. The engine and the radiator are both spic and span clean (I do the engine cleaning/detailing myself). The culprit is the fan clutch. Does anybody know if this part is rebuildable or the sealed/disposable type?

Does anybody know if this part is rebuildable

It's a throw away.

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Thank you guys for all the technical assistance. I was hoping that the clutch fan can be repaired (fill up with silicone oil). Well, I'm to go and buy an OE clutch fan assembly.

There are a couple of webpages around that show the innards of fan clutches and how to repair them  - they are not specific to the Suzuki and may or may not be applicable - google will find them.

Now - were I in your situation, I'd be thinking about replacing the fan with an electric one - something that I'm already considering even though the fan clutch on my GV is working fine.

The theoretical advantages are less noise at startup (a vehicle with a clutch type fan has a distinctive sound at startup), reduced fuel consumption and improved throttle response - however the reason I want to do it is none of those - I want to be able to switch off the fan before driving into water.  A spinning fan lifts the water and throws it around the engine compartment, increasing the probability of your getting the electrics wet, even in cases where the water is not that deep.

Thank you fordem for the suggestion. Yes, I agree with you regarding water splashing all over the engine bay during river crossings and mud crossings. This is the reason why my zuki fiberglass buggy has its radiator mounted at the back of my rig.

I just want everything OE in as far as my Grand Vit is concerned. By the way, the clutch fan, I found out upon dissassembly, is rebuildable since there are about 4 screws holding the clutch together. This will save me a fortune!

rebuildable since there are about 4 screws holding the clutch together

Personal opinion here. By the time you source, receive and install the internals (seals, bearings, spring and whatever ELSE is in there), at minimum purchase quantities too proly, you'll be installing them in housings that are suspect to begin with. Will the new seals hold up in a worn housing? Can you disassemble the unit without "special" tools? Are there repair instructions to support your efforts? How long do you want to wait on fixing your ride while you forage for parts?

Don't know, but at the price of a new unit (relatively cheap), you'll be wasting your time and effort on a "prayer" fix.    

Sure, anything can be fixed. But at what cost?

C'mon Max - where's the harm in opening it up and taking a peek?  As a kid I took all my toys apart and for the most part, put them back together too.

Yeah - it is important to recognize that repairing things is not always cost effective, but if all it's taking is your time and a few bucks, then it can be a very satisfying way to spend a few hours.

Last week my son & I swapped out the springs on my other Suzuki (maybe I should say 'his' Suzuki), and the time it took us, if I had to bill for it would have paid the mechanic five times over - but - it was a slow day (yes, it was a working day), we lost no income, we had fun doing it and he learned something new.

Oh I'd dissect one for sure, just out of curiosity.

To me though, small components like these aren't worth the effort to fix. Kinda' like alternators, starters and water pumps. For instance. I've got the tools to turn commutators, press in bushings, bead blast, etc. but at the low pricing of MASS produced, warrantied and readily available (quick vehicle turn around) new and rebuilt stuff out there, why bother?  

On the other hand, I've spent countless hours meticulously restoring cars, tractors and you name with little to no chance of recouping a profit JUST to feed my need to tinker and say "I did this".

That said, I have great memories of my son and I working on HIS vehicles. Memories that I cherish. So we share the same feelings in that aspect. In fact, I'm heading out to Denver next week, FOR a week, and we're lining up things to putter on!  

Well, I  agree with both of your insights. Having a passion for vehicles particulary Suzukis, having the clutch fan repaired is more of a challenge and curiousity for me. Of course, if I am not satisfied witht its performance, I would eventually use a brand new OE clutch fan. But the personal satisfaction I get from doing this on my own is unmeasurable.

Just a comment.

This appears to be a slightly different situation to the one I had detailed.

With reduced forward motion due to heavy traffic the air flow through the radiator would be insufficient to cool the engine without assistance from the fan and with a failed fan clutch, that assistance would not be available, so engine temps would rise.

There is a cooling system sensor that will force the a/c compressor clutch to drop out, whilst still leaving the condenser fan running - the idea being to drop the a/c heat load and allow some level of additional cooling using the a/c fan.