Finally Broken Down

finchy40 · February 23, 2018

My IS250 with 10 years and 170k miles under its belt broke down today.

AA say the air conditioning unit has failed causing the car to stall and it wouldn't restart.

Has anyone experienced this or got any idea how much it will cost to repair?

Thanks.

Britprius · February 23, 2018

38 minutes ago, finchy40 said:

My IS250 with 10 years and 170k miles under its belt broke down today.

AA say the air conditioning unit has failed causing the car to stall and it wouldn't restart.

Has anyone experienced this or got any idea how much it will cost to repair?

Thanks.

From your description it sounds like the AC compressor has seized. New compressors are around £350 + fitting, and re-gassing. On eBay used units start at around £25.

John.

jumbojake · February 23, 2018

on other cars I;ve owned before, if you turn off AC, it disengages the magnet/solenoid and the pulley will freewheel ... of has that bearing siezed?

Texas · February 23, 2018

That's not good!....

could it just be the electric clutch and can this be swapped out? Also can the engine be ran with a shorter aux belt that does not go over the AC pulley or is it physically not possible to do that on this engine?

paul m.

finchy40 · February 23, 2018

Thanks for or the quick responses folks. AA man said he thought by cutting the belt the engine may run but I'm not sure of the longer term issues that might cause.

Does not having that belt mean anything other than the ac not being operable?

Britprius · February 23, 2018

Modern compressors do not have clutches. They have an internal solenoid that allows them to idle without compressing.

John.

Texas · February 23, 2018

With the belt removed there will be no power to the water pump (WP) and the Altenator (GEN) so you would not be able to physically drive the car very far without implications! Looks very tight if not impossible to by-pass the AC by using a shorter belt.

Linas.P · February 23, 2018

9 minutes ago, finchy40 said:

Thanks for or the quick responses folks. AA man said he thought by cutting the belt the engine may run but I'm not sure of the longer term issues that might cause.

Does not having that belt mean anything other than the ac not being operable?

I had exactly the same issue, just around 160k. Stuck A/C compressor.

Generally, if you turn it off A/C, compressor clutch should disengage and turn freely, by your description it sound like you have faulty/stuck clutch as well.

In my case I got A/C compressor reconditioned and all in all paid £310 instead of £900 for OE replacement and fitting.

See here:

Linas.P · February 23, 2018

2 minutes ago, Britprius said:

Modern compressors do not have clutches. They have an internal solenoid that allows them to idle without compressing.

John.

not sure about that, because there are certainly "compressor clutch relay". Unless that relay control solenoid and is just wrongly named in user guide.

Britprius · February 23, 2018

Just now, Linas.P said:

not sure about that, because there are certainly "compressor clutch relay". Unless that relay control solenoid and is just wrongly named in user guide.

Not knowing the actual compressor fitted to the car you could be correct, but many compressors now have no clutch just a valve operated by a solenoid that allows internal circulation of the coolant gas without compressing it.

John

finchy40 · February 23, 2018

Big thanks to everyone for the advice. As usual, you guys have come up trumps.

much appreciated.

stevet · February 24, 2018

Mine did exactly the same at 10 years old. Luckily still under warranty so Lexus fitted all new and strangely all the AC piping as well.

Sent from my Iphone using Tapatalk

finchy40 · February 24, 2018

A further question please:

Having now established that it is indeed the seized ac compressor, does anyone know how I could get hold of a belt which is the right size to bypass the ac pulley.

Texas · February 24, 2018

If you are sure that if you bypass the AC pulley the belt will not foul on any other parts then the way forward would be to determine the length of the new belt required by measuring the length around all the pulleys ( not AC obs!) in millimetres as aux belt serial numbers have the length in mm in there somewhere!

Everything you wanted to know about polyvee belts here https://simplybearings.co.uk/shop/Belts-Multi-Ribbed-Poly-V-Belts/c4601_4791/index.html

Paul m.

finchy40 · February 25, 2018

Thanks Texas. Much appreciated.

Fishboy · March 1, 2018

Sorry to hear about your breakdown. Quick question, did you always have your AC running? I've heard that not using AC often enough can cause early failure with the compressor lunbrication system, having said that 10 years and 170k isn't bad going, my VW Golf failed within 3 years, apparently a common fault.

finchy40 · March 1, 2018

Hi Fishboy

You may well be right with your observation.

The air con hadn't been used for a few months and then used quite a bit for a couple of weeks.

Fishboy · March 1, 2018

Years ago when AC was a rare extra one of our managers had a Ford Galaxy Ghia as a company car, trouble was he was so tight he never used it as he said it dented the fuel economy, it was less than 2 years old before the AC unit packed in, warranty job big bill for Ford. I always have my climate control on, it's like your home central heating really, just keeps the car at the right temp for me regardless of what's happening outside. My IS250 is now 8 years young with 115k on the clock and I'm hoping for a good few more miles without any grief.

Linas.P · March 2, 2018

Mine was used literally 100% of the time, but I agree that not using A/C might hurt it more then using it often. As for impact to fuel economy - at least on IS250 it is so negligible I never managed to find any reasonable correlation. I ten to believe it is less then 0.2MPG on average. Can hurt more sitting in traffic with A/C ON, but have no impact on motorway, probably saves fuel in comparison with open windows. As well I always use air re-circulation and only let the fresh air in at the start and in the end of commute in quite side roads/parking lot.

Tyre Tread · March 2, 2018

10 minutes ago, Linas.P said:

Mine was used literally 100% of the time, but I agree that not using A/C might hurt it more then using it often. As for impact to fuel economy - at least on IS250 it is so negligible I never managed to find any reasonable correlation. I ten to believe it is less then 0.2MPG on average. Can hurt more sitting in traffic with A/C ON, but have no impact on motorway, probably saves fuel in comparison with open windows. As well I always use air re-circulation and only let the fresh air in at the start and in the end of commute in quite side roads/parking lot.

I don't mean to be pedantic (or maybe I do) but how would you be able to say "As for impact to fuel economy - at least on IS250 it is so negligible I never managed to find any reasonable correlation." when you already said " Mine was used literally 100% of the time..."

It will impact MPG. How much is debatable and dependant on many factors.

Personally I rarely, if ever, turn off the aircon on any of my cars in which its fitted.

Linas.P · March 2, 2018

The way I could tell is obviously by keeping it ON and then OFF for the same or very similar journey. So yes I tend to keep it 100% of the time ON (when it works), but few times I have deliberately turned it off to check if it would make any difference to MPG and could not tell any difference in fuel consumption. As well, at least now my A/C does not work - seems to be faulty pressure sensor on the inlet, and comparing similar period fuel consumption from last year when it was working I cannot see any measurable difference. So based on my observation from 3 separate IS250 and over 100000 miles the difference between ON and OFF is so negligible that I can barely tell the difference.

I tend to believe that on the cars with smaller engines it might be more, but on something car as heavy as IS250 with 2.5L v6 there are almost no difference. As well based on my research from IS mk2 owners on US forum the consensus is that A/C increases fuel consumption by 0.5-1% and because the fuel consumption as you mentioned varies based on many factors it is almost impossible to tell the difference between A/C ON and OFF.

johnatg · March 2, 2018

I agree that it makes negligible difference to fuel economy (even on smaller engines such as our Seat Mii) and any vehicle aircon should be kept on at all times to minimise problems. (Although, Linas, keeping it on hasn't avoided your problem!). It is essential for the lubricant (suspended in the gas) to be circulated whenever the engine is running.

Linas.P · March 2, 2018

Well mine was a little bit special case, obviously mileage was a factor, but after discussion with A/C specialists we reached conclusion that following had happened - my A/C had a leak somewhere, when I got the car for Lexus to service (standard full service) they have re-gassed the system as sort of complimentary service, but had not properly checked for leaks. That resulted in one of the lines bursting just 3 miles from dealership and instantly wasting all coolant and lubricant, because I was accelerating at the time this damaged compressor which seized in result of sudden loss of coolant and lubrication under load.

Fishboy · March 2, 2018

That information on AC brings me to my next question, which I can probably answer myself? To the best of my knowledge and I've had the car over 5 years it's never had a re-gass. I'm sure the AC works as well as the day I bought it and I run it all the time so does it need one or will it create a problem I don't have?

jumbojake · March 2, 2018

I'm thinking the same.... I know a few places do a £30 empty, refill and test ... so I might get them to do that anyway, just to ensure the lubricant is refreshed (even though a/c appears to be ok)