help diagnose subaru problem

[qube 3570]

Not sure where to put this so ill try here admins feel free to move it.

As our work wagon we have a 1996 subaru legacy 250t. Done 173,000 kms now and had it for about a year.

From a while ago, the car has been struggling to acccelerate. Its only when the car is cold. But warming it up doesnt help. It goes away after a minute of driving though so its not that bad..

It feels like the car has no power and it like sputters along. Kind of like its not receiving enough fuel?

Any ideas? Thanks in advance

[BreakMyWindow 1874]

Take it to Subtech in Penrose - Dave there is very good.

[Driftit 2069]

Usually caused by a stuffed Oxygen Sensor on those things.

Rough Idle, Poor Economy, loss of power.

[gjm 3258]

Not enough fuel, or too much? What's the economy like - any worse than when you bought it?

How much oil does it use?

Is it losing any coolant? Does the engine overheat at all? Any white smoke on start up?

The 250t has the 2.5 twin cam engine, and can be prone to head gasket failure which (on the twin cam) manifests as bubbles in overflow reservoir (this is gas from combustion), an oily residue on the walls of the coolant overflow reservoir, and occasional engine overheating.

It's not as easy to diagnose as the gasket fails 'internally' - there's no obvious outward signs of failure, and any symptoms can be difficult to reproduce.

If it is a head gasket problem - check the radiator cap. Actually, do this anyway. These fail, allow too much pressure to build up in the cooling system, and could cause the original problem.

If it is overheating at all, get it sorted ASAP. Repeated overheating will crack a cylinder head, and in the case of the 2.5, possibly the block.

See here for more info on this.

Of course, it could be something else entirely.

[Allanw 1071]

Tell me you only run it on 95 octane

Old spark plugs/leads can do this too - they idle fine on all 4, but with a bit of load on, they can drop a cylinder, but still feel fairly smooth. I found it more common when cold/running rich.

The original knock sensors crap out, but are really cheap. Ususally you can notice small flat spots/hesitation as the revs climb though

With the head gasket thing, make sure the cooling system is well serviced - if there is any doubt, a "T" fitted to partially bypass the heater WELL BEFORE any head gasket signs show can help a lot. The heaters clog over time, and the ONLY way the thermostat knows to open, is by the temperature of the coolant through the heater back to the thermostat.

Slightly unrelated, but I once did headgaskets on one of these that had been run to hat, the timing belt covers were melted and starting to sag down the front of the engine After I saw that... I drove it myself for 3 hours too, before stripping it for repair

They're really good motors when sorted - I still run one in my VW van, and it gets a hiding smetimes.

[qube 3570]

Take it to Subtech in Penrose - Dave there is very good.

I've had very bad experience with subtech in penrose, and i live pretty close to there. wont be going back. not saying hes bad or not nice, just not a good experience and its just my personal case.

Usually caused by a stuffed Oxygen Sensor on those things.

Rough Idle, Poor Economy, loss of power.

Ok, will have a look into the O2 sensor. cheers

Not enough fuel, or too much? What's the economy like - any worse than when you bought it?

How much oil does it use?

Is it losing any coolant? Does the engine overheat at all? Any white smoke on start up?

The 250t has the 2.5 twin cam engine, and can be prone to head gasket failure which (on the twin cam) manifests as bubbles in overflow reservoir (this is gas from combustion), an oily residue on the walls of the coolant overflow reservoir, and occasional engine overheating.

It's not as easy to diagnose as the gasket fails 'internally' - there's no obvious outward signs of failure, and any symptoms can be difficult to reproduce.

If it is a head gasket problem - check the radiator cap. Actually, do this anyway. These fail, allow too much pressure to build up in the cooling system, and could cause the original problem.

If it is overheating at all, get it sorted ASAP. Repeated overheating will crack a cylinder head, and in the case of the 2.5, possibly the block.

See here for more info on this.

Of course, it could be something else entirely.

its actually driven by my dad most of the time and he hasnt said anything about the fuel economy. it seems to be about the same.

have just done a fresh oil and filter change so i will keep an eye on the oil usage.

not losing any coolant and car has never overheated. i havent checked for white smoke but i dont think so. will check.

i know about the headgasket failure problems on these cars. Have previously owned 1 years ago that didnt overheat but i was a total car noob back then. probably had no water in the tank.

to the best of my knowledge the car as no headgasket/overheating issue (yet!). we always make sure there is enough water and the engine temp gauge has never gone past the midpoint so far.

Tell me you only run it on 95 octane

Old spark plugs/leads can do this too - they idle fine on all 4, but with a bit of load on, they can drop a cylinder, but still feel fairly smooth. I found it more common when cold/running rich.

The original knock sensors crap out, but are really cheap. Ususally you can notice small flat spots/hesitation as the revs climb though

With the head gasket thing, make sure the cooling system is well serviced - if there is any doubt, a "T" fitted to partially bypass the heater WELL BEFORE any head gasket signs show can help a lot. The heaters clog over time, and the ONLY way the thermostat knows to open, is by the temperature of the coolant through the heater back to the thermostat.

Slightly unrelated, but I once did headgaskets on one of these that had been run to hat, the timing belt covers were melted and starting to sag down the front of the engine After I saw that... I drove it myself for 3 hours too, before stripping it for repair

They're really good motors when sorted - I still run one in my VW van, and it gets a hiding smetimes.

yes, always run on caltex or bp 95 (not bp 98).

I am thinking it might be the spark plugs too. they probably havent been replaced in years.

even though i mentioned above that i dont think there is a overheating/headgasket issue, could water in the engine cause the spark plugs to get wet and cause the misfire(?) and it goes away after some time as the water is evaporated? (dont really know what im talking about here lol)

We have had the whole radiator and cooling system drained (to the best it possible could be, apparently some design flaw in which its super hard to drain from the heater core because its located higher up than the rest of the system?.. had the car on a steep angle to do this and it was refilled properly.. or so im told)

anyways, im pretty sure the heater isnt clogged anymore after all that ^

the cambelt? is due soon i believe, i will take a look at the timing belt and covers but seems okay from what i can see lol.

and yes, i agree they are great motors. i know there is a lot of hate for them because of the notorious overheating blown headgasket issue but like any other car, looked after well they're not so bad. apparently there is an updated steel plated gasket or something that prevents this issue.

//

anyways thanks for all the help so far on a BMW forum.

much better to get local advice that one from some random guy behind a keyboard halfway across the world

[yng_750 247]

They also go through knock sensors which can come and go with temp

[Ahmedsinc 414]

even though i mentioned above that i dont think there is a overheating/headgasket issue, could water in the engine cause the spark plugs to get wet and cause the misfire(?) and it goes away after some time as the water is evaporated? (dont really know what im talking about here lol)

Hell no, dude. Water inside the cylinder for any reason is always bad news. Only thing that should get your plugs wet is flooding with fuel, or oil entering the combustion chamber from worn rings or stem seals. Water won't cause a misfire, though it will happily shatter rods, snap cranks, and kill an engine in other gory ways

[yng_750 247]

Most of these horror situations dont go away with car getting warm.

Id guess electrical if it changes with temp.

But all really a stab in the dark.

[qube 3570]

Like i said i have no idea what im talking about lol.

Will look into the things mentioned.

Thanks

[Driftit 2069]

Most of these horror situations dont go away with car getting warm.

Id guess electrical if it changes with temp.

But all really a stab in the dark.

O2 Sensor goes away a little when the car is warm. It is the most common issue with these old Brobarus.

[qube 3570]

Ok will check o2 sensors.

Dad told me knock sensor has been replaced.

[HaNs 226]

+1 for Subtech

[evljat 1]

If you're still looking for a workshop I recommend Highbrook Automotive in East Tamaki. They are well recommened on Subaru forums too. If you decide to go there ask for AJ and tell him that Jag sent you.

[qube 3570]

Ok thanks thats helpful. Not too far too

[MrT 0]

I have a 2003 legacy wagon (my sensible car) that would stutter on acceleration when cold. Even foot to the floor wouldnt make any difference, nor would it kick down until at least 5 minutes worth of driving. Turned out to be a dirty oil problem as i hadnt serviced it for a year and a half. The 4 solenoids needed replacing as they were sticking shut due to the dirty oil. Brand new ones cost about $240 each but my mechanic had a spare motor lying around that we pinched them from. Once the old oil was flushed at, we added some cleaner to break down the grime some more and did another oil change a few months later. Car runs like new.

[qube 3570]

Ok we have just done the oil but prior to that it was prettt bad. Will check those things! Cheers

[MrT 0]

If the oil was bad prior to a change, then the solenoids will still probably be rooted no matter how oil changes you do. Good luck!