I have a 2007 Forrester. With just a few weeks left on the drivetrain warranty the turbo died. I'm wondering why it died and what I can do to prevent it happening again. I guess I'm asking if this is a common problem with this model.

 

TIA,

 

koneall

Did you find out why the turbo died?

 

Has the oil been changed regularly? Do you drive the car hard?

Lack of oil changes will kill them for sure. And always let the car idle for a little while before you shut off the engine. Especially after you run it hard.

Most common reason for a turbo to "die" is lack of regular on time oil changes. Proper maintenance is crucial for the longevity of a Turbo. Missing even one change or regularly going over the change interval leads to heavy wear on the bearings, and eventually acids in the oil combined with the heat from regular driving will score the bearings to the point of failure. At which point you start blowing white smoke.

 

Hard driving and heavy use of the turbo creates high temperatures in the turbo case. The turbo doesn't have a system for dispersing that heat on it's own. It relies on fresh oil, and in some systems antifreeze to help keep the unit cool. If the engine is turned off while the turbo is still "hot" (after a hard run) the heat can actually burn off the oil inside the bearings. Leaving residue, and causing the turbo to "dry start" on the next engine start. This again leads to wear of the bearings, which will eventually lead to failure.

 

2 main rules for turbo longevity. 1. Change the oil regularly and often.

2. Give the turbo time to cool, about 2 minutes of idling, before shutting off the engine.

Thanks for the help. We get the oil changed between 3500 and 4000 miles. IS that too long?

 

koneall

For a turbo, you really should consider synthetic - your change interval is fine. The added heat and cylinder pressure's will benefit from a synthetic oil. It will handle the heat of the turbine shaft housing without cokeing - which is generally why the turbo's fail - lack of lubrication will get them quick. Properly lubed and cooled they can easily last 250k miles.

 

I would go with Mobile 1 since it's availible anywhere, and probably *increase* your oil change interval to around 5 or 6 thousand miles. Synthetics not only withstand the heat better, but they last longer as well.

 

GD

wow im glad it was under warranty. Fairtax4me is right about letting it sit for a while

Thanks for the help. We get the oil changed between 3500 and 4000 miles. IS that too long?

 

koneall

 

For conventional oil, yes that's probably too long. :-\ Driving habits have a big impact on oil life. If that is 4k miles of mostly highway criusing, then that may be fine. But for 50/50 mixed or mostly city driving you would want a shorter interval of about 2500 - 3000 miles with conventional oil.

 

Synthetic oil in city driving I would think 3500 - 4k miles would be fine. Mostly highway you could stretch that to 5000+ if you're not driving really hard.

For the most part, I drive two miles to work, drive home for lunch then home for dinner, six days a week. Maybe once a month I'll drive on the interstate 20 miles to the next town. Once every three months I'll drive three hours on the interstate to Salt Lake City. Overall the turbo gets little use.

 

koneall

banjo bolt......search it on the other boards, legacygt.com is where i would go to to search banjo. may be the cause.

All the stock turbos have coolant in them for cooling, and the stock design allows for convection cooling currents to occur after the engine is shut off.

For the most part, I drive two miles to work, drive home for lunch then home for dinner, six days a week. Maybe once a month I'll drive on the interstate 20 miles to the next town. Once every three months I'll drive three hours on the interstate to Salt Lake City. Overall the turbo gets little use.

 

koneall

 

Ouch!

Short trips= Prime territory for sludge. Sludge is just as bad, and can be much much worse than simply going past regular oil change intervals. Combine sludge WITH extended/missed changes and you have a recipe for disaster. No joke, it is nasty nasty stuff.

http://www.schleeter.com/images/BMW%20oil%20sludge.JPG

http://delanytowing.com/candiscorner/media/blogs/a/oil-sludge.jpg

 

I haven't heard many sludge stories with Subarus, but no car is immune to sludge buildup. There are lots of cases with Toyota Saab and VW engines suffering extensive damage and even locking up due to sludge. Best way to avoid it is to change the oil at scheduled intervals, and to go a step further use synthetic oil.

 

Not saying that sludge caused the problem in your particular case, but if you care about your engine, you need to get out and drive it further and more often. It needs to get up to normal operating temperature and stay there for at least 15 to 20 minutes (the longer the better) on a regular basis, at the very least once a week. Idling in the parking lot doesn't count because that doesn't replicate the conditions the engine will face while driving.

 

Turbo's don't generally go bad from being "under used" but the conditions created when the car is driven too softly or for not enough time can lead to wear and failure of the turbo.

banjo bolt......search it on the other boards, legacygt.com is where i would go to to search banjo. may be the cause.

 

I think this is exactly what happened. Stupid filter in the banjo bolt.

Well the Forrester is on its way back. My wife and a friend drove the 200 miles yesterday to pick it up. Shortly after leaving the engine light came on. They went back and had that fixed. But by then it was getting dark and neither wanted to drive at night so they found a motel. Now they're headed back. The mechanic confirmed the problem was caused by not changing the oil often enough. Also driving mainly short distances without letting the turbo cool. So from now on we change the oil every 3000 miles, I sit in the car for a couple minutes before turning it off, and hope my daughter does the same when she leaves for college in the fall, taking the Subaru with her.

 

Thanks for all the help. I assume I won't be back here anytime soon.

 

kevin

I'm back. About 100 miles outside of Ogden the brand new turbo died. She was in the mountains and it died on a particularly steep slope. It still runs but not too well. She called and Ogden Subaru said to bring it back. So she's heading back to Ogden at 40MPH.

 

kevin

If I were you, I'd be seeking fuel and time compensation from the dealer. There is no way that a new turbo should break on the drive home unless the dealer tech's didnt hook everything up right, or they put a used turbo instead of a new one.

 

There are low pressure turbos so they should last a bit long than a turbo on say a WRC rally car

wow! i would get an oil analysis.

This doesn't usually happen with the Forester turbos. They don't have the same turbo and motor issues that the Legacy GT's and the Baja turbos have. That and 3500-4000 miles is fine between oil changes if you use synthetic. But regular oil should be changed more often!! And yes, definitely let it warm up and cool down!!

There is a reason a lot of LegacyGT Turbo, Outback Xt turbo, etc are for sale for less than kbb right now, all at say about 60k miles....

I wish you the good repair results. And, I doubt it was lack of oil changes or doubt it was lack of letting engine run at cool off. It was a design flaw, in the banjo bolt filter clogging, there are tons of people on LegacyGt.com with this problem........

And, I doubt it was lack of oil changes or doubt it was lack of letting engine run at cool off. It was a design flaw, in the banjo bolt filter clogging, there are tons of people on LegacyGt.com with this problem........

 

 

what is the fix for this 'banjo' bolt design flaw??

They take the oil screen out. But unfortunately, the stuff that clogs the screen in the first place is metal shavings from the main bearing:-\. But again, this was only a problem with the Legacy GT's and Baja turbos. They had a completely differently designed block from the 06+ WRX's, STi's, and the Forester XT's

If I were you, I'd be seeking fuel and time compensation from the dealer. There is no way that a new turbo should break on the drive home unless the dealer tech's didnt hook everything up right, or they put a used turbo instead of a new one.

 

There are low pressure turbos so they should last a bit long than a turbo on say a WRC rally car

 

I'll second that. They did something wrong, there's just no way a brand new turbo goes bad in under 100 miles.

That or the dealership didn't properly diagnose the original problem. The turbo dying was a symptom not the problem.....

Exactly could be not enough oil. AKA bad oil pump, id still lean more towards that banjo bolt not being replaced. Also was there a oil change done HOPEFULLY at the same time as the turbo swap? Maybe a bad oil filter!

another helpful tip is to keep the revs down until the car is up to temp..

 

cold oil = high oil pressure... you can do damage to the bearings in the turbo from this. ALWAYS let your car reach operating temp before romping on it. If I don't have time to let the car warm up before heading somewhere, the car won't see more than 3k rpms until it's up to temp and that is light acceleration and NO boost.