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Slipping clutch Pages: 12

AC Amiture on Sat July 04, 2009 11:55 AM User is offline

Year: 2000
Make: Mitsubishi
Model: Mirage
Engine Size: 1.5
Refrigerant Type: R-134
Ambient Temp: 100-110
Country of Origin: United States

Well I'm back again with this Mitsubisi.

Problem:

Slipping compressor clutch.

I just installed A new compressor the Accumulator was replaced at the same time.

This compressor was replaced because the old clutch burned up.

Worked fine for a few days the my daughter reports "Not cooling right."

Here is problem now:

Runs OK for about 5-10 minutes then cooling starts to decrease (measured with an air temp gauge).

Under hood check reveals that clutch starts to slip intermittently with chirping or squealing noises.

I took it to a shop.

They discharged and recharged.

They say charge and oil are OK.

They say voltages are OK.

However I am going to check this myself.

Best advice they can offer is that my new compressor is bad and I should return under warranty.

I'm not happy with this advice any thoughts from you guys?







TRB on Sat July 04, 2009 11:59 AM User is offlineView users profile

What brand of compressor aka four seasons, compressor works, Delphi? What are the pressures readings when the clutch fails? Are all the fans working correctly when clutch fails?

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AC Amiture on Sat July 04, 2009 12:40 PM User is offline

I'll get gauges on it and get the other info as soon as I can. I won't be able to until this afternoon at the earliest.

THX

AC Amiture on Sat July 04, 2009 10:49 PM User is offline

OK.

A lot to write.

First the compressor:

It is a TAIQ MS090 from Arizona Mobil Air

Now what I observe:

Before start up the clutch resistance is 3.3 Ohms.

After start up I checked the voltage to the clutch and got 14.5 Volts.

After connecting the gauges and before turn on the gauges are LOW (above 120) HIGH (130).

After startup and stabilization LOW (25-28) HIGH (185-190)

After 3-4 Minutes, Clutch begins to cycle OFF 5-10 Seconds on 25-30 Seconds ON.

Air temp at the duct exit is 58 Degrees.

During the OFF part of the cycle LOW rises to 55 and HIGH drops to 145.

During the on part LOW goes to 28 and HIGH to 195-200 then disengage.

When clutch engages there is a click and a slight "chirp" as though there is a small slip at engagement.

This is all at idle.

Allowed it to run for 15 Min.

During this time cycled ON 25-30 seconds then OFF 5-10 Sec.

After 15 Min. I tried increasing speed. This results in extreme slipping and squealing when it tries to cycle ON.

Ambient Temp. 100 Degrees

So! Every thing looks fairly normal but the clutch just slips??????

Any ideas?






Chick on Sat July 04, 2009 11:09 PM User is offlineView users profile

Is the high side rising all the time it's running until it shuts off? I would check the clutch gap first, and what was the ambient temp when you posted the pressures?? after it runs fifteen minutes or so and begins shutting down, check the coil again.. let us know what the ohms are then.. Make sure no oil is getting on the clutch either from the outside or leaking shaft seal??


-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

Edited: Sat July 04, 2009 at 11:10 PM by Chick

AC Amiture on Sat July 04, 2009 11:33 PM User is offline

"Is the high side rising all the time it's running until it shuts off?"

Nope. It goes to approximately 195 then stabilizes until next disengagement .

"I would check the clutch gap first, and what was the ambient temp when you posted the pressures??"

The ambient was 100 Degrees.

This is an almost new compressor and the gap appears to be quite narrow. However, I'll measure it later tonight or tomorrow.

"after it runs fifteen minutes or so and begins shutting down, check the coil again.. let us know what the ohms are then.."

It starts to cycle after 3-4 Min. Then cycles OFF 5-10 Sec. ON 25-30 Sec.

Is this normal??

"Make sure no oil is getting on the clutch either from the outside or leaking shaft seal??"

I'll see what I can see. There is no obvious oil. I'll look carefully.

I am also going to try cleaning out the gap with some brake cleaner.

I'll let you know what happens.

Thanks for your suggestions.

AC Amiture on Sat July 04, 2009 11:36 PM User is offline

Forgot.

I'll also check the resistance after running when I have a few minutes.

I'll let you know.

TRB on Sun July 05, 2009 12:00 AM User is offlineView users profile

Is the clutch slipping or cycling more than you would like as there is a difference between these 2 issues! What are you vent temperatures? Does it cycle more on low blower than high blower or the same?

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AC Amiture on Sun July 05, 2009 12:16 AM User is offline

OK.

Gap is .015

Cleaning with brake cleaner gave very slight improvement. (The chirp when it engages at idle seems to be gone however it still squeals some when I rev the engine and it engages)

Resistance after running for a while climbs to 3.7 Ohms.

Any help appreciated.

AC Amiture on Sun July 05, 2009 12:34 AM User is offline

"Is the clutch slipping or cycling more than you would like as there is a difference between these 2 issues!"

It is defiantly slipping. I asked about the cycling because I am not sure how often it should cycle.

"What are you vent temperatures?"

58 Degrees while it works. When it cycles it cycles between about 64 Degrees and 58 Degrees


"Does it cycle more on low blower than high blower or the same?"

Interesting. At HIGH blower during Idle it did not cycle. As I stepped the blower down it cycled more and more frequently. How does that affect the squealing though?


Thanks

Chick on Sun July 05, 2009 6:00 AM User is offlineView users profile

I'm not sure if I'm reading this right, but the clutch is different than the pulley, and squealing is usually from the pulley slipping.. meaning are you sure the whole compressor clutch isn't slipping (clutch plate and pulley) and not just the outer clutch driver? Sounds like belt tensioner to me, yes it should cycle when a certain evap temp is reached, which is why it will do it less on high fan, air passes over the evap faster and doesn't let the temp drop as fast.. Check your belt tension or get a new belt..

-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

AC Amiture on Sun July 05, 2009 9:37 AM User is offline

"meaning are you sure the whole compressor clutch isn't slipping (clutch plate and pulley) and not just the outer clutch driver? Sounds like belt tensioner to me,"

I'm just about certain it's the clutch.

The belt is tensioned by an adjusting screw and not a spring tensioner.

Changing the tension to several different levels seems to make no difference.

"yes it should cycle when a certain evap temp is reached, which is why it will do it less on high fan, air passes over the evap faster and doesn't let the temp drop as fast.. Check your belt tension or get a new belt.."

I have inspected the belt and it looks OK but I'll check again and see about a new one.

I'm really frustrated with this.

It'll be worth a new belt if it will fix the problem.

I have thought of a couple of other things to check in addition.

Let me know if you have any other ideas.


Thanks

TRB on Sun July 05, 2009 11:56 AM User is offlineView users profile

There is no mention of flushing the old oil and debris from the system. Was this done and what was your procedure? How much oil has been added along with the charge level? Any chance of posting a video clip of this acting up?

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

iceman2555 on Sun July 05, 2009 10:19 PM User is offlineView users profile

The condenser is restricted. More than likely, the cycling is a result of excessive discharge temperature/pressures that are opening the temp sensor located on the compressor case. This is becoming quite a normal experience with these late model Mitz's and Chrysler 'look a likes'. When the OE scroll take a 'dump' the debris field produced is un real. This restricts the inlet of the condenser and thus the excessive discharge pressures/temps to cycle the temp sensor.

-------------------------
The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

AC Amiture on Mon July 06, 2009 10:17 PM User is offline

This has a new condenser. Put in about 1.5 months ago on advice from a professional who said it had a restriction and a hot spot.

Wouldn't a restriction show up on the gauges?

AC Amiture on Mon July 06, 2009 10:27 PM User is offline

I did some electrical measurements to day.

See if these numbers give any one any ideas.

Coil connector to ground: 3.3 Ohms

Current when clutch pulls in: 3.4 Amps

After running and beginning to cycle current drops to about 3.15 Amps

I imagine this is due to coil heating.

Hot coil measures 4 Ohms.

All of this doesn't look out of the ball park to me but:

The clutch still slips when engaging at more than idle speed???????



TRB on Mon July 06, 2009 10:40 PM User is offlineView users profile

Quote
Originally posted by: TRB
There is no mention of flushing the old oil and debris from the system. Was this done and what was your procedure? How much oil has been added along with the charge level? Any chance of posting a video clip of this acting up?


Any answering to these questions?



-------------------------
When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

Chick on Tue July 07, 2009 7:12 AM User is offlineView users profile

Was the condenser changed after the compressor failure? being new won't mean much if it went thru a compressor failure.....

-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

AC Amiture on Tue July 07, 2009 8:11 AM User is offline

There was no compressor failure.

There was a clutch failure.

The compressor was replaced because I could not find a replacement clutch.

The system was cleaned up. ( flushed) when this was done.

Oil was "amount to replace oil drained from old compressor" plus 10 Ml.

The accumulator was changed at the same time.

Sorry no video. I'll post one if I get access to a camera.

As previously stated the shop that had it told me to "warranty the compressor"



AC Amiture on Tue July 07, 2009 8:19 AM User is offline

Sorry.

One mistake.

I'm not fully awake yet.

The Oil = Drained oil = 10Mil is incorrect.

That was from previous work.

This time it was cleaned out so the amount called for in the published data (I don't remember what that was right now) was added.

iceman2555 on Tue July 07, 2009 9:21 AM User is offlineView users profile

High side (liquid) pressures may not indicate a restriction in a condenser. High side (discharge) pressures are more reliable for this test.
Still believe it is the condenser. It was replaced and the operated on a vehicle that later suffered a 'clutch' failure....am I correct. A large percentage of clutch failures can be traced to an increase of internal compressor rotation friction. This friction is normally due to lack of lubrication flow to the compressor...the result is a possible release of debris that may restrict the condenser.
A good test....simply measure the condenser inlet temps and outlet temps. This will give a indication of possible restriction. An excessive temp drop is normally an indication of a restriction.
Or test the temp of the discharge line and compare with a pressure/temp charge.
Another indicator, to me, is the lack of high side pressures....the pressures indicated are a bit low for a fully charged system operating within the ambient temp range posted and the statement that the compressor operates at idle, however, the clutch slips at elevated RPM. Elevating the PRM increases compressor efficiency....thus discharge pressures are increased...the condenser does not flow 100% and the build up of discharge pressures results in a the condition described.

-------------------------
The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

TRB on Tue July 07, 2009 9:51 AM User is offlineView users profile

I have to agree with Ice on this there is something causing your clutch issues. This is the second "clutch" failure in a short time frame. More research needs to be dome to determine why you continue to have a repeated issue!

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

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