Auto RX in 1995 Subaru Impreza 1.8

[RoadRaceJosh]

This is my 67 year old Mother's car. She's had it since 1996 and it's gotten fair care over the years, but has developed a valve train tap on the passenger's side which comes and goes. This car has hydraulic lash adjusters unlike later models. I put a pint of Marvel Mystery Oil in the crankcase about a week before doing an oil change and adding the Auto-RX. I cut open the dealer installed Subaru oil filter to see what was in there. If I can I'll post how many miles that filter was in service, but the records aren't here with me at the moment. I installed a Purolator Classic oil filter along with Chevron 10W30 and the Auto-RX. I'll change the filter between 1,000 and 1,500 miles to see what we're getting with the Auto-RX. This is just another case study so take it for what it's worth.

 

[Johnny]

So, how many miles on your Mom's car and what were the OCI? What oil has been used in this car?

 

[RoadRaceJosh]

The car has just short of 118k miles. I don't know the average OCI, but it's been run on conventional oils its whole life. The only problem I want to resolve it the valve train noise, but I'm curious to see if we catch anything else.

 

[sw99]

Looks like the filter trapped a bunch of debris. Nice!

 

[ChuckBerry]

So, that filter represents one week of MMO use?

 

[RoadRaceJosh]

Originally Posted By: ChuckBerry
So, that filter represents one week of MMO use?


The MMO was in the crankcase for one week. The filter had around 4k miles of service in about 6-8 months. Sorry the records aren't better.

Since the valve train noise is the only problem I'm attempting to rectify I thought the MMO might have a chance and would at least give the cleaning a jump-start. I cut the filter open out of curiosity more than anything.

The Auto-RX has only been in about 250 miles and the valve train noise is still present.

 

[unDummy]

Timing belt/tensioners/idlers... ever replaced?

 

[Quest]

1995 Subaru 1.8 may be the type that requires manual valve lash (tappet) adjustments in order to tame the tappetty noise.

Look around and see if you can confirm that part (I'm not specialised in Subarus) and if so, consider getting a valve lash adjustment done, regardless of whether you are on cleaners (AutoRx or MMO) or not.

Q.

 

[RoadRaceJosh]

Yes, the timing belt and associated parts have been replaced. Mom dropped a bunch of money on service at the stealership.

1995 Subaru EJ18 engines have hydraulic lash adjusters (HLA). The HLAs were later changed to solid adjusters to reduce friction.

If the noise were constant I would have just opened the engine and replaced the bad parts.

 

[OneEyeJack]

How's the cooling system? Any signs of problems. What has been done to maintain the system? There are other things that need a look besides oil.

 

[Not the Autorx Frank]

Well I guess MMO couldnt fix it....

 

[RoadRaceJosh]

The cooling system is fine.

If the Auto RX doesn't do the job I have Kreen on hand. If that doesn't do it then I replace a lash adjuster.

I don't think 500 miles with the MMO was sufficient time for it to work and it may have worked if used for a full OCI. It's true the noise was still there after ~500 miles MMO use, but that's not enough info to condemn MMO.

Once again, all I'm trying to do here with the Auto RX is to save from having to replace the lash adjuster.

 

[Cause4Alarm]

take the adjuster out, take it apart and clean it. 9 times out of 10 it's just sludgyness plugging it up

 

[demarpaint]

Originally Posted By: Joshua_Skinner

If the Auto RX doesn't do the job I have Kreen on hand. If that doesn't do it then I replace a lash adjuster.

I don't think 500 miles with the MMO was sufficient time for it to work and it may have worked if used for a full OCI. It's true the noise was still there after ~500 miles MMO use, but that's not enough info to condemn MMO.



500 miles isn't giving MMO a chance to do anything especially, if you are trying to clean something up. 500 miles might be OK to maintain engine cleanliness, and even at that it probably still isn't enough, a 1000 miles would be a better idea. When trying to clean something a full OCI is the best bet. Good luck with your project, keep us updated.

 

[Trav]

I don't think 500 miles is long enough for any additive to work to its full potential no matter how good it is.

 

[demarpaint]

Originally Posted By: Trav
I don't think 500 miles is long enough for any additive to work to its full potential no matter how good it is.


I was thinking the same exact thing!

 

[PontiacFan]

Originally Posted By: demarpaint
Originally Posted By: Trav
I don't think 500 miles is long enough for any additive to work to its full potential no matter how good it is.


I was thinking the same exact thing!


I totally agree.

 

[RoadRaceJosh]

Sorry for the long interval between updates. The AutoRX didn't do a thing for the noise and the Kreen didn't either as the noise kept coming and going. At this point the noise is there more often than not so the lash adjuster is going to be replaced. For what I spent on the AutoRX I could have just replaced the lash adjuster, but my time/labor cost would have been higher.

 

[Mystic]

That kind of makes me think about my experience with Auto-RX. It did seem to stop a seal leak. Replacing the seal on the front drive Saturn would have been expensive, but I should have just insisted that the dealership replace the seal.

 

[Trav]

Hold the throttle at 3K RPM for at least 30 seconds. See if that clears the noise.