p.monro

Rough running at low revs is often caused by a vacuum leak. There may be no codes displayed. The leak is often in the hoses which, with an older car, have become cracked or split at their ends. In my 1991 legacy the leak occurred at the junction between the air inlet duct and the inlet manifold. I spent a lot of time looking for it but the agent found it real quick. I guess he put a vacuum gauge on the manifold to check for vacuum leak. You could try squirting oil over the various air inlet joints to see if this improves performance as this acts as a temporary seal. It is an old technique but personally I have not had much success with it.

Have you checked there is spark at the plugs. You can do this by hooking up a good plug and then cranking or running the motor whilst looking for spark. maybe the suggestion of the igniter by a previous writer is worth looking at

Your proposed oil squirting technique may work. I guess the idea is that it temporarily closes the small leak so that you can see if the engine runs better. You would need to be sure to cover the whole perimeter. Perhaps a thick grease may be better. If you had a vacuum gauge I would check the manifold vacuum. Haynes says it should be 425 to 550 mm (about 16 in) mercury and not fluctuate. If it is 10 to 25kpa (2in Hg) below normal and fluctuates at the low reading suspect an inlet manifold leak at an intake port. Haynes also gives a lot of other methods for diagnosis from the vacuum gauge reading.

Could it be that you have a vacuum leak at the gasket on the air intake on the passenger side. At idle, the vacuum is highest and so there would be too much air. This would give the impression of the car running the same with the injectors disconnected. At power the car would seem to run OK because the furl/air balance is more near the correct value. That is my guess at your problem

If you have checked the codes and there are none then I suspect that your idle problem is a vacuum leak. This lets too much air in at idle. At higher revs it is not so odvious because the vacuum is lower. It should also happen with the engine both hot and cold. The usual cause is cracked vacuum hoses but also the 2 air inlet manifold gaskets may be leaking

Yes I agree with Josh Depending on how the coolant temerature sensor fails . If after checking the codes you disconnect the battery for say 30 minutes this should reset the alarms. The fans may then not turn on at start depending on how the alarm is processed. My guess is that you have had the check engine light up sveral times and not taken any action so after say 5 or 10 such events the ECU has latched the fans up

When using the word "dip" I mean the action one takes by lowering the head light beam so as to provide better visibility to on coming traffic. The headlights are "dipped" by operating the lever provided for this purpose on the steering column. Do you use another word for this? If the lights appear to be dimmed this could be as a result of the dipping relay chattering as a result of poor voltage caused by an open joint or a short circuit

Interesting---- Few have commented on the radiator. I would have expected a failure of the plastic end cap by 200,000. However I note that many respondents come from colder climates so presumely this failure is temperature related. Failures are both distance and age related. My 91 legacy on 190,000 km plus is now starting to show age problems, rust and seal (air manifold gasket) failure. It and my 92 legacy have both had radiator end cap failure but nothing major

You are correct. Personally I think you are on the right track. Like you, I would concentrate on why the lights dim. I presume you mean dim (not dip). If the lights dip then this is an electronic problem similar to the tacho. But if the lights dim it is probably a power problem and should be more easily traced. I think you should look for either a short to earth that is enough to drop the electronic voltage but not enough to blow the fusable link. Somewhere between the battery and the ignition switch. or a dry joint Perhaps the ignition switch is the problem. I presume that on your vehicle the ignition switch also turns off the lights. A faulty switch explains all the problems you describe.

Maybe the flood water damaged one of the sensors and this is why the CE light is on. Go to this link and it will tell you how to find out which sensor is bringing you CE Light up http://www.surrealmirage.com/subaru/subaru.html

You don't say what maintenance you have done. Chances are that like me you dont do anything until a problem occurs. So start with a bit of a clean up, plugs, ignition wire clean and inspect, battery check, clean air filter

The next thing to do is check the codes. Josh (legacy777) has a web site with the procedure which I presume works with an outback. Have a look round this forum for the link to his site and previous enquiries about reading codes. The legacy will run satisfactorily with some of its tranducers out of spec but eventually,when they get too far out, performance will suffer.

My daughters 2.2 Legacy had idle problems hot and cold but there were no alarms. I checked the Haynes manual and did all the recomended things like plugs, air filter, clean throttle body, check for vacuum leaks. I also tried to remove the Iac valve but gave up because of the difficulty. However the Iac valve did not seem likely because it is supposed to to be closed when hot and I simulated that by pinching the hose. All that did was stall the car. So in the end I gave up and sent it to the dealer who fixed it quick. Vacuum leak on the inlet manifols gaskets. He replaced two of them.

You need to check the codes as Josh says. A faulty temperature sensor can bring up intermittent check engine light. In my case it occured about 5 minutes after start up and was up for about 3 minutes. However when I checked the resistance of the sensor it appeared to be within specification. This went on for about 6 months before it finally caused a problem by latching up all the radiator fans. Perhaps this is the cause of your rough idling also. It is one of the transducers that causes hard starting. Regards Peter

I would back the hairline crack in the radiator end cap. These caps are made of plastic and is a usual cause of loss of water from the radiator. When the radiator pressure rises the crack opens a very small amount to discharge water and when the pressure is relieved the crack closes. The closed crack is almost impossible to detect visaully. You can perhaps get an indication of the leak be observing if the bottom of the radiator is moist. It can be tested by filling the radiator and then running the car to raise the pressure but you will need to look in the correct spot at the time it discharges because it will just squirt it out and the close the crack. The best method is a pressure test Regards Peter

I guess how the receiver drier removes moisture is the question. If it is a chemical reaction then I guess it will not be removed by vacuum. However I understand others have done it with no problem. At high vacuum I guess any old oil will be removed. I have had some experience with vacuuming oil filled equipment and in some systems the oil will boil at 20in Hg. Now I can not say what the boiling temperature is for R12 oil at high vacuum but my guess is that it will all boil off before the high vaccum can be achieved so (I believe) it will pull it out of the receiver. So my belief is that as long as it is vacuumed with a good pump for say 1/2 hour it should be OK. It would be a good idea to fit a vacuum gauge to check that the vacuum goes to 50 microns to confirm this belief. I like your idea of how to get a vacuum pump. If my grandad had not died 60 years ago I would take a look in his workshop but I doubt he would have 6 spare pumps. Ha. Regards

Why change the receiver / drier. My view is that if it is vacuumed at 50 microns for say 1/2 hour then there will be no water left. There was an earlier posting by someone who had done that. My problem is the compressor. You can get them in the USA for $200 os less. Here in NZ they are about US$500. I bet I can get shipping for less than us$300. As for the refrigerant and valve I am going to try to buy a part used cylinder form a AC tech. The small cans here are about $US24 each instead of the price you guys pay arround $5 I believe How are you going to get on with vacuuming again Josh or have you got a pump now? Regards

Hi patcal I am working on my AC at this time having received an estimate for about US$500 to fix it when I expected about $US 250. The AC workshop claim they found leaks in the TX valve and the shaft seal. I have the TX valve out and it has a leak caused by corrosion under the "O" ring seal which I have cleaned and am getting ready to pressure test. I believe I can fix this US$80 item for nothing. I will also clean the evap whilst it is out. It is covered in rubbish. Then I will pressure test the system and evaluate the shaft seal leak. My hope is that I will live with a small shaft seal leak. I am also looking for R134A and the kit. I expect to find it at an auto store. My guess is that if you are low on gas then you will have a leak somewhere Have a look at Josh's link. It has good info on prices. I expect to pay about US$15 for the kit and Josh has the gas prices. Haynes manual also has a good section on AC Regards Peter

Here is the link to Josh's original article http://pub110.ezboard.com/fultimatesubarumessageboardsfrm6.showMessage?topicID=110.topic

Just got an estimate from the AC specialist for $784 to fix. This is more than air conditioning is worth to me so I will think about doing it myself. The estimate was for labour $220, oil and O rings $18.5, Evacuate and charge to 134A $100, Denso drier $79, Shaft seal TV12C/14C Carbon $73.48, Gasket set ND TV12/TV14/C $66.12,TX valve Block n/Denso R12 $107.32, Retrofit adaptors $15.95 and with $87.13 tax this comes to $784. The DENSO Tx valve aparantley leak at the thread. Can this be sealed somehow without having to buy a new one? What prices do you guys pay for this stuff? Regards Peter

Hi RedLance It is 1993 model and will have the R12 for sure. I know its history from new and it has had nothing done to the AC. Ok I will be aware about a Drop in unit Thanks for telling me about the hoses and the oil. So far I reckon it sounds like about $100 for hoses, $20 for oil and say 2 hours $150 coming to say $300. I suppose there is a shaft seal is that likely to need replacing? Thanks Peter

Thanks Redlance you have it just right. I was shopping round for a pressure switch and got on to an AC workshop and they told me that the switch was for low refrigerant pressure, from leaking. The same thing happened last year at this time but it came right and I used the AC all last summer so I guess the refrigerant has slowly leaked out. I was interested to hear about the O rings. That piece of information will be of use when I take it into the AC workshop. The system still has the original refrigerant. R16 isn't it. Will they top that up or replace it with the latest version. Regards Peter

Hi Josh Thanks for your reply. Yes replacing the switch would be good. I have had the connector off and checked the switch continuity and it is definitely open when it should be closed to pull in the compressor clutch. I was hoping that if I kicked the compressor over it may free the switch up. I am surprised about your suggestion that it may be possible to replace it without depressurising. Have you any more info on this aspect. Thanks Peter

My air conditioning does not work. The compressor will not run when the AC switch is pressed and the fan running. I have traced the problem to the pressure switch which is latched open. I had this problem once before and it came right by itself but it seems to be stuck this time. Any one know of a quick fix. If I bridge the contact (to force the compressor on) will it clear it?

You can check if the fuel pump is operating. When you turn the key to the position just before it engages the starter motor there should be a soft purr sound for about 2 seconds. You can hear this better if you get some one else to turn the key while you listen at the fuel fuel filling pipe with the cap removed. The sound is very faint and you need to do it in a quiet place. When did you have the fuel filter replaced? It is supposed to be done every 25,000km or 12 months. If it is like mine it may never have been done after 9 years and 140,000. But perhaps it is just blocked. Have you just got the car? perhaps the previous owner had dirty fuel. But first check for the pump sound. If you can not hear that it is possibly the pump Although not unknown, it is not common