Timing Chain Replacement - Do I or Don't I

[jimbo747]

2007 Outback with the H6 engine.  Over 295,000 miles, mostly (80%) highway. Oil and filter changed religiously (every 5,000 to 6,000 miles)

I've just developed a dripping oil leak at the bottom of the timing cover.

I have two philosophies:

1) Preventive Maintenance is good

2) If it ain't broke, don't fix it.

I have hear somewhere that Subaru timing belts should be replaced at 300,000 miles, but I cannot verify this.  The shop manual (yes, I have the official shop manual) only gives service intervals for timing belt, not chains.  Other sources say only replace the chains if I am overhauling the engine.  I am not having any timing issues, nor am I hearing any rattling sounds coming from the engine.

So, do I simply remove the cover, clean it and reseal with 3-Bond (and replace the crank seal), or should I replace the chains at the same time?

Your thoughts and experiences are greatly appreciated.😀

 

[Daskuppler]

1 hour ago, jimbo747 said:

2007 Outback with the H6 engine.  Over 295,000 miles, mostly (80%) highway. Oil and filter changed religiously (every 5,000 to 6,000 miles)

I've just developed a dripping oil leak at the bottom of the timing cover.

I have two philosophies:

1) Preventive Maintenance is good

2) If it ain't broke, don't fix it.

I have hear somewhere that Subaru timing belts should be replaced at 300,000 miles, but I cannot verify this.  The shop manual (yes, I have the official shop manual) only gives service intervals for timing belt, not chains.  Other sources say only replace the chains if I am overhauling the engine.  I am not having any timing issues, nor am I hearing any rattling sounds coming from the engine.

So, do I simply remove the cover, clean it and reseal with 3-Bond (and replace the crank seal), or should I replace the chains at the same time?

Your thoughts and experiences are greatly appreciated.😀

 

If you're in there, I would just do the timing job.  Especially since the cover is smothered in RTV.  That's a terrible job.  I had a block replaced and they didn't even bother cleaning the cover, they just ordered a new one.  I did the same thing on my Xterra.

Is it worth doing 90% of the work only to wonder if you should have done the chain?  Or have a failure that could have been prevented over a few hundred in parts you already had your hands on.

[GeneralDisorder]

Get a JDM replacement engine. The fact that you made it to 295k without a head gasket failure is a miracle. Don't spend a dime doing any superficial to that engine it's going to blow a HG and you'll have wasted the effort.

GD

[jonathan909]

GD and I are at odds over this because he's practical and knows what he's doing, and I'm stubborn, cheap, and live by the old Stiff Records maxim:  Try everything once except incest and folk dancing.  I just did two HG jobs on the older ('01) H6 this past summer.  Assuming yours is more-or-less the same (I haven't done a revised H6 yet), that furshlugginer timing cover alone adds a day to the job.  Seriously, in addition to cleaning all that RTV, you're dealing with ~150 bolts, and that means it's all but certain you're going to get some stripped heads that'll add to the fun.  I didn't change the chains, and so far it's been running great (one is in service, the other on standby and hasn't seen any actual miles yet).  So I'm happy with the effort and the result, and actually had fun when it came to reinstalling the chains.

Edited December 1, 2022 by jonathan909

[azdave]

I'm lazy but I like a clean driveway. I would not do anything for a small oil drip on an engine approaching 300K except put a diaper on it and drive. My original 2003 WRX engine is at over 200K now but has a small drip. I fold up multiple layers of toilet paper or paper towel into a small square and place it at the drip point, held up with neodymium magnets or other clips/wires to keep it in place. That absorbs any drips between maintenance intervals and I put in a new absorber with each oil change. I know it's a ghetto fix but it works for me until it gets really bad (and then I get out the duct tape). Ha! 

[heartless]

i would be half inclined to agree with GD - get a JDM replacement...

the other half is inclined to agree with jonathan - do headgaskets at the same time as timing chain work... and yeah, 300k is about right on the timing chain/guides service life from everything i have read as well..

we have an 06 LL Bean Outback that just got retired at around the 250k mark due to "issues" - coolant loss, rough running, etc, all pointing to headgasket failure - torn on what to do with it right now..
do we "yank and fix" or "replace".... the rest of the car is in decent enough condition that it would be a shame to scrap it. for now, it has been parked up on the car trailer for the winter.
Considering the "issues" this one has, thinking a JDM replacement is probably the best option for it.

 

[88SubGL]

Unless oil is running out the timing cover about as fast as you pour it in, run it till it dies. As big and heavy and as many bolts as that cover has, I wouldn’t mess with it.

[1 Lucky Texan]

maybe the waterpump's leak-hole is where the problem is? I think it can leak EITHER oil or water depending on which side's seal is compromised.

 

but yeah, I think a JDM engine is a great fix. A DIY repair could be a fun project for some people, but with more risk.

[idosubaru]

If you’re handy reseal the cover in the car and call it a day. You don’t have to pull the engine. 

[jonathan909]

2 minutes ago, idosubaru said:

If you’re handy reseal the cover in the car and call it a day. You don’t have to pull the engine. 

Yabut... Removing the cover should still be considered nontrivial since there's a good chance that at least one of those 65 front cover screws is stripped.  If that's the case, you're at least going to be pulling the rad to give you enough room to work at getting it out, and more if it gives you a bad time.

[idosubaru]

Yes look at the bolts - are they rusty?  Because there’s a good chance they strip even if they aren’t rusty. Impact screw drivers are great but can’t use those insitu. Come up with a stellar method of removing them. EZ Outs are not the way. There’s like 60 of them so 3 minutes per rusty bolt is 3 hours just to remove bolts. 

I would not replace the chains. On a 300k H6 the exhaust valves may be tight, carbon build up in the heads, head gaskets may go soon, water pump may leak, and I’m sure it’s using at least some oil? The timing chains are far enough down the priority list they’re not a big deal. I know it happens but ive never seen a broken H6 Subaru chain. I’d consider the water pump more than the chains. At which point maybe you do chains and pump since they have to come off to replace it and you’ll have nice clean visible timing marker colored links on a new chain to work with rather than trying to eyeball which one it is on a 300k chain. 

[jonathan909]

48 minutes ago, idosubaru said:

Yes look at the bolts - are they rusty?  Because there’s a good chance they strip even if they aren’t rusty. Impact screw drivers are great but can’t use those insitu. Come up with a stellar method of removing them. EZ Outs are not the way. There’s like 60 of them so 3 minutes per rusty bolt is 3 hours just to remove bolts.

I successfully used the external bolt biter extractors we discussed recently after nothing gripped the Allen head cavity (these are socket head cap screws).

Edited December 3, 2022 by jonathan909

[GeneralDisorder]

Besides doing this every day for a living and that really making it lose the shine..... I think precisely because it has lost it's shine for me I'm going to give you the most prudent and cost effective advise. My goal is to get in and get out as quickly and effectively as possible while maximizing long term customer satisfaction, profit, and minimizing my labor and expenses. 

JDM engine. Period. I wouldn't even consider wasting a shop hour looking at a 295k engine. That's a door stop till the scrap truck rolls through. 

I suppose if you have a ton of time and are still on the "mechanic learning curve" and wish to use this as an educational tool........ NAW that's just silly. Keep it and tear it down for educational purposes after you JDM swap it and then POUR the contents of your workbench into the scrap truck after you are done taking it to pieces to find out what a nightmare you avoided. 

GD

[heartless]

only problem being JDM H6s are in short supply right now.. other half has checked several places...

any recommendations on who to deal with?

 

[1197sts]

I bought a JDM H6 for my son's 2001 LL Bean, it ran fine for a few thousand miles and is now pumping coolant into the overflow reservoir and has bubbles. There are plenty of people who have had good luck with the JDM engines, but from my perspective there is no way to know what you're getting with a JDM engine it is a gamble as far as headgasket longevity is concerned. When I purchased mine the seller documented a compression test, that's all the info you can usually get.

Also from what I have seen prices are going up especially on the EZ30 the earlier version, shipping is going up, even if you do the labor yourself it is not what I would call inexpensive.

 

[idosubaru]

3 hours ago, 1197sts said:

I bought a JDM H6 for my son's 2001 LL Bean, it ran fine for a few thousand miles and is now pumping coolant into the overflow reservoir and has bubbles. There are plenty of people who have had good luck with the JDM engines, but from my perspective there is no way to know what you're getting with a JDM engine it is a gamble as far as headgasket longevity is concerned. When I purchased mine the seller documented a compression test, that's all the info you can usually get.

Also from what I have seen prices are going up especially on the EZ30 the earlier version, shipping is going up, even if you do the labor yourself it is not what I would call inexpensive.

 

Yep, JDM isn't as attractive now as it used to be - they're pricey and old which does headgaskets no favor.