Sorry to start another TOD thread...

[fj401968]

I've read a lot of HLA noise oriented posts here and I have a pretty good handle on causes and fixes. None-the-less I have a question:

 

If HLA noise can be caused from aeration of the oil due to faulty oil pump gaskets which in turn cause the lifters to go flat... is this something that can come and go with oil changes?

 

I've not had my current Subaru for all that long. When I first got it, I changed the oil and after that it started ticking (although I don't think it was on all cylinders). I figured it was dirty lifters and added Seafoam and drove it around for several days but to no avail. I used some motor flush and changed the oil again (the oil had a fair amount of sludgy junk in it.). I put in fresh 10W 30 and some more Seafoam and drove it for another several days... one day the ticking stopped during a short coffee run after being parked for a few minutes after my 30 min morning commute. It purred like a kitten for a month after that with nary a tick. I figured it had been dirty HLAs and considered the problem fixed.

 

Then one day... I let the car idle for a couple hours while I got sidetracked talking to a pretty lady at work... when I went back out to my car it was ticking. DRAT... After that I added MMO and Seafoam and drove it for several days. The ticking seemed to get worse. I'm sure the oil was a bit thin at this point although oil pressure was reasonable. I flushed the engine again (it was really ticky while it idled for 5 min with heavy duty engine flush in there) and figured I'd put fresh oil in it to see if that helped although at this point I was suspecting the TOD was from leaky oil seals aerating the oil (as an aside: this Subaru doesn't leak a drop of oil anywhere!! unlike my former Subarus). After the oil drained I noted some more sludgy stuff but less than the first time. I then added 10W 30 with nothing added to it. It ticked upon starting it. I let it warm up a bit and then in a spastic moment I just revved it up HARD and for a good several seconds. The ticking quieted and stopped! The car has been purring nicely again and I haven't heard a single tick in over 300 miles of driving. It is quiet upon immediate starting and quiet through any range of RPMs. I sure like my Subaru better when it isn't ticking.

 

Did I have dirty lifters that were fixed by changing oil or did I have thin, additive laden oil that became more susceptible to aeration and changing the oil put it back to a threshold that was tolerable by my possibly aging but not yet gone oil pump seals?

 

I was going to pull the oil pump and replace seals over the Christmas holiday break but now that the engine has quieted down again I'm just driving it and enjoying the car and wondering if the oil pump is fine.

 

Thanks in advance for the input.

 

Tracy

 

'87 GL wagon

 

former Subarus: '81 GL wagon, '88 GL wagon, '90 Legacy wagon

[Tycho]

If you have chronically low oil pressure, there's really nothing that can be done for the TOD.

 

I had low oil pressure with a warm engine (fine at cold start) on a fresh rebuild (re-used the old bottom end bearings as they were all had .0015" to .0017" oil clearance...BIG MISTAKE).

 

Not wanting to split the crank case, I've done the following:

Pulled all 8 lifters and cleaned them (full disassembly/gasoline soak/reassembly)

Replaced all 4 lifters in the noisy passanger side bank with some low milage units

Re-sealed the oil pump

Replaced the oil pump with a new unit (after re-sealing the old unit did nothing as the gasket was fine)

Checked and re-checked the O ring on the cam box (put a new one in each time)

Heavier oils

Lighter oils

etc etc etc.

 

It's gotten much better (new oil pump and some 0-40 mobil 1 keep the lifters happy unless I really beat on the motor) but I still have one lifter that lets go when I bring the engine temp up with heavy load. This lifter is not bad, it's just at the very end of the oil path and subsequently gets the least pressure. I think the "one noisy lifter means one bad lifter" thing is a common misdiagnosis based on my own personal experience. Some lifters see less oil pressure than others based on their physical location in the engine...especially if oil pressure is low to begin with.

 

There's no doubt a number of causes of the TOD and several solutions, but the only permanent one in my case is going to be a fresh set of bottom end bearings with a nice moly disulfide coating on them and .0010" or less oil clearance on the mains and rods. When there's an intrinsic oil pressure problem none of the "tricks" will fix the TOD.

 

As a side note, I'd rather set lash every 30,000 miles than enjoy the "convenience" of HLAs... I've never had a 4age tappet go flat...

[fj401968]

If you have chronically low oil pressure, there's really nothing that can be done for the TOD.

 

<snip>

As a side note, I'd rather set lash every 30,000 miles than enjoy the "convenience" of HLAs... I've never had a 4age tappet go flat...

 

What a saga...

 

My oil pressure seems pretty decent for an EA82. It rides around the same range as my former Subarus did. When I'm cruising down the highway on a warm engine it is close to 45.

 

I agree about the 'convenienc' of HLAs. I love the simplicity of the engine in my '68 FJ40 Landcruiser and I loved the EA81 in my '81 GL wagon. I wish I'd kept that car.

[idosubaru]

oil pressure can be compromised by a bad gasket/o-ring between the block and the oil pump. pressure will bleed off when one of the o-rings gets "sucked in" to the wrong port. it'll bleed off internally, so oil loss isn't an issue.

 

i've pulled at least 3 or 4 oil pumps with a sucked in oil port, happens all the time. i've saved them a few times to take pictures, but have always ended up discarding them...one just a couple weeks ago. it'll come and go depending on many factors.

 

occassionally you'll find thicker oil (20W-50) will alleviate the TOD temporarily, some have had it go away switching to thinner oil. depends on alot of things.

[idosubaru]

found a picture of the oil pump gasket port i was talking about. i know lots of people that have seen this and i've seen it many times myself. it is by far the most common cause of TOD that i have seen on the cars i've worked on.

 

hhh....picture won't upload..... i can't load anything on USMB for some reason?

 

here's a link to the picture at xt6.net of the failed oil pump gasket:

 

http://www.xt6.net/forum/viewtopic.php?p=40320#40320

 

you'll notice the gasket port on the left is round, the one on the right should be as well. but it has a divot in it from where it gets "sucked" into the actual port and no longer seals around the edge.

 

if someone can grab that picture and post here that would be helpful as i can't load it here.

[fj401968]

Will TOD from a sucked in Mickey Mouse ear come and go as mine has or am I likely plagued with residual sludge? I have no idea how frequent the oil changes were in its past.

 

Right now my '87 GL wagon with approx 200,000 miles on the odometer is purring like a kitten at all RPMs whether cold or warmed up. I expect it to tick again though at some point and I'm trying to determine if I should just bite the bullet and tear into the oil pump (and timing belts while I'm at it).

 

Thanks for your good input Gary.

 

Tracy

 

 

 

oil pressure can be compromised by a bad gasket/o-ring between the block and the oil pump. pressure will bleed off when one of the o-rings gets "sucked in" to the wrong port. it'll bleed off internally, so oil loss isn't an issue.

 

i've pulled at least 3 or 4 oil pumps with a sucked in oil port, happens all the time. i've saved them a few times to take pictures, but have always ended up discarding them...one just a couple weeks ago. it'll come and go depending on many factors.

 

occassionally you'll find thicker oil (20W-50) will alleviate the TOD temporarily, some have had it go away switching to thinner oil. depends on alot of things.

[idosubaru]

yes this kind of failure can "come and go" so to speak in terms of the TOD. that yours is there one day and not the next is nothing new to the subaru's i've driven and worked on in the past 15 years. HLA noise is usually a sign of some other problem as you can tell from the replies, so the diagnosis isn't necessarily a science. the oil pump is relatively easy to fix so replacing the seals that cost a few dollars is well worth the effort.

 

if it's quiet now, i wouldn't worry...well i wouldn't worry either way as it's not good for you. if it comes back, try some more MMO, Seafoam, ATF and no skimpy skimp on the oil changes K?

[Tycho]

 

Indeed, ol mickey wasn't looking so hot when I did my rebuild last year (looked the same as that one)...so I thought my woes were over! Sadly no.

 

From my conversations with the guys who fix these things all the time, the tick is usually fixed w/ a new mickey or a new oil pump (the front seal on the shaft can leak air into the oil if it's on the outs). In my case I just had multiple causes (only one cause now).

 

Since you say you have 45 PSI on the highway with a warm engine, I'd bet that you don't have any problems in the oil pump area. Keep the oil clean and maybe try a wider range oil (thinner when cold, the same or thicker when hot) to assist pump up on cold start (I've found the 0-40 gives me better pressure everywhere than 5-30 or 10-30).

 

Super clean oil is key for any HLA car. There's a check valve in the HLA that consists of a spring loaded ball bearing that sits in a socket of sorts. Any particulate contamination in the oil will prevent the bearing from seating and "sealing" the lifter oil chamber. This obviously leads to uncontrolled bleed down which manifests itself as TAP TAP TAP TAP. Saturn tappet type HLAs have "chronic" failure in cars that don't get regular oil changes. The ATF/seafoam thing combined with a return to proper oil change intervals often "cures" these engines also.

[Frank B]

I think the additives cleaned the crap out of the lifters, and your frustration-driven high revving "cleared out" the last of it. Keep up on the oil changes and use a quality filter like WIX. Maybe you could use some rislone or mmo in the oil to keep them clean.If it comes back, spring for a new pump.

[fj401968]

I was hoping for something more concrete like: 'yeah if the problem comes and goes, it's not the mickey mouse gasket'... oh well, if the oil pump seals aren't a big deal to change then I'll go ahead and do it when I get around to doing the timing belts. In the meantime, I'll continue to change the oil often and throw in some MMO/Seafoam from time to time. Hopefully it will just keep running quiet.

 

Thanks everyone for the good information on this common problem that can sometimes be elusive.

 

Tracy

 

yes this kind of failure can "come and go" so to speak in terms of the TOD. that yours is there one day and not the next is nothing new to the subaru's i've driven and worked on in the past 15 years. HLA noise is usually a sign of some other problem as you can tell from the replies, so the diagnosis isn't necessarily a science. the oil pump is relatively easy to fix so replacing the seals that cost a few dollars is well worth the effort.

 

if it's quiet now, i wouldn't worry...well i wouldn't worry either way as it's not good for you. if it comes back, try some more MMO, Seafoam, ATF and no skimpy skimp on the oil changes K?