Subaru Outback Forums banner

White smoke coming from under hood on driver side

1 reading
18K views 22 replies 7 participants last post by  cardoc  
#1 ·
Hey everyone,

I own a 2000 Subaru Outback Limited with about 192k miles. Just recently, there has been white smoke coming from under the hood. Specifically from the header or manifold on the driver side. From what we’ve read, we suspect it’s a valve cover gasket issue. We still aren’t sure where it’s exactly from. Also, that it may be a leak of some sort, not sure if it’s coolant or oil yet.

Other info: it’s a used car we bought, don’t have much information on repairs such as HG but doesn’t seem to be the HG.

Any help is appreciated, thank you.
 
#2 ·
The head gasket will leak oil if it still has the single layer steel gasket. Can you take a picture of the bottom of the engine, both sides, getting the area from the valve cover to the oil pan? You should be able to post the picture as an attachment, or open the pic up and copy/paste it in the response window.

There is also heater hose that runs under the driver side of the engine.

The head gasket will not leak coolant.
 
#5 ·
Hey cardoc,

Thanks for your reply! These are some pictures that I took when first discovered earlier today. I don’t have the chance right now to take pictures of what you exactly asked, but I thought these might help until I’m able to.
 

Attachments

#7 ·
Well the good news is you don't have a rust problem. Is this car manual as the bellhousing bolts have been 'touched' before and the earth straps missing, so assume a clutch job at some point. @cardoc will be able to answer more fully as I'm not too familiar with gen 2's but to me it looks like the valve cover gaskets on both sides have gone. There's definitely oil stains on the exhaust down pipes. Does it drip oil overnight and how much are you topping up with ?
 
#10 ·
We do plan on replacing the valve cover gaskets and spark plug tube seals while we’re at it if that is is the issue! It doesn’t drip much at all and I just topped off with about a quart/little less before it hit right below the Full mark.
 
#8 ·
Head gaskets are leaking oil. The oil is dripping onto the manifold making the smoke.

A valve cover leak wouldn't have oil on an engine mount like what is in your pics. And all that oil is mostly around the HG seam.

Repairing, and updating the head gaskets is a relatively easy job. You can monitor the oil level until you fix it.

My suggestion when doing this type repair is change everything on the engine at once. This depends on when the timing belt was changed out last whether you do that, but all new gaskets, timing components, thermostat and coolant along with plugs and ignition cables as needed. You can adjust all the valves while the engine is out. You can reseal the separator plate. Clean the intake, throttle body and IAC. Remove all the carbon from the pistons and heads. If it's manual, change the clutch set and release bearing. Clean the engine compartment while the engine is out. Fix all the body grounds while the engine is out. If your PS hoses have a leak, another thing that is easier while the engine is out. It also gives you the opportunity to easily flush the heater core, clean debris from the front of the radiator and make everything nice and spiffy.

I knock these out in a day start to finish. Your results may vary, even if an indie shop does the work for you, unless it's me. There are threads on this forum that outline HG replacement on these engines and many people have done it over a weekend.

You can even catch up on trans and diff oil service at the same time.

As for parts, MLS head gasket set, (not FelPro, the gaskets and seals don't fit), Mitsuboshi timing kit (no water pump) with Japanese bearings and tensioner, Subaru thermostat, or you can get an AISIN or Mahle, NGK plugs and wires. If your water pump does not have JAPAN or AISIN on the front, then get an AISIN timing kit with a pump that has the Mitsuboshi belt. Make sure you get a metal water pump gasket or pick one up from Subaru.

After you're done, it's good for another 100k until any maintenance on the engine will be due. The clutch, if it's manual, depends on the driver.
 
#9 ·
Head gaskets are leaking oil. The oil is dripping onto the manifold making the smoke.

A valve cover leak wouldn't have oil on an engine mount like what is in your pics. And all that oil is mostly around the HG seam.

Repairing, and updating the head gaskets is a relatively easy job. You can monitor the oil level until you fix it.

My suggestion when doing this type repair is change everything on the engine at once. This depends on when the timing belt was changed out last whether you do that, but all new gaskets, timing components, thermostat and coolant along with plugs and ignition cables as needed. You can adjust all the valves while the engine is out. You can reseal the separator plate. Clean the intake, throttle body and IAC. Remove all the carbon from the pistons and heads. If it's manual, change the clutch set and release bearing. Clean the engine compartment while the engine is out. Fix all the body grounds while the engine is out. If your PS hoses have a leak, another thing that is easier while the engine is out. It also gives you the opportunity to easily flush the heater core, clean debris from the front of the radiator and make everything nice and spiffy.

I knock these out in a day start to finish. Your results may vary, even if an indie shop does the work for you, unless it's me. There are threads on this forum that outline HG replacement on these engines and many people have done it over a weekend.

You can even catch up on trans and diff oil service at the same time.

As for parts, MLS head gasket set, (not FelPro, the gaskets and seals don't fit), Mitsuboshi timing kit (no water pump) with Japanese bearings and tensioner, Subaru thermostat, or you can get an AISIN or Mahle, NGK plugs and wires. If your water pump does not have JAPAN or AISIN on the front, then get an AISIN timing kit with a pump that has the Mitsuboshi belt. Make sure you get a metal water pump gasket or pick one up from Subaru.

After you're done, it's good for another 100k until any maintenance on the engine will be due. The clutch, if it's manual, depends on the driver.
Lots of assumptions in this post such as the OP having the equipment to pull the engine as well as automotive know how. Anytime a professional mechanic says something is easy to do it’s definitely a relative term! The YouTube video I followed to replace my spark plugs in my 2013 3.6R this past weekend said it was relatively easy but I got stuck halfway through on the rear most cylinders and had to have a neighbor help me.
Also the same YouTuber says if you use the turbo four-cylinder head gaskets you won’t ever have the problem again so be sure to use those!
 
#11 ·
@bugman

I assume nothing except that people have the ability to do things that they previously believed they did not. Your experience with an H6 spark plug is relative. Maybe the engine wasn't jacked up enough. Maybe the YouTuber wasn't clear on everything. I don't know.

I did post the possibility of going to an indie. Cost at an indie would be over $2k nowadays, where someone at home with space can rent equipment at a part store and getting the limited amount of tools which cuts the cost drastically.

People on this forum from all kinds of backgrounds have taken an H4 out of the car, repaired the HGs and put it back with success.

@WA.OB Your major oil leak is the HGs. If you look under the car you will most likely see a lot of oil sprayed on the undercarriage behind the engine and trans. It's been leaking for a good while and since it's burning on the exhaust, it's gotten worse.

If you are in WA state, as your user name suggest, you're in Subie land and there's shops you can inquire with to compare repair cost.
 
#12 ·
The other question that one could ask is , that's a 22 year old car, and If I'm not mistaken, Washington salts the roads. What shape is the rest of the car in ? A clean whole engine swap may be cheaper and work out best in the long run.
 
#15 ·
CV joint grease is really thick and when it gets slung around it clumps up all over where it hits. You have oil coverage on the head and block as well as the engine mount and the engine cradle. CV grease would sling over the back side of the head, on the engine cradle, part of the steering gear assembly and the underbody of the car as well as hit part of the exhaust. Kind of hard for it to hit the manifold on the driver side of the car though. The passenger side it'll hit real easy because the pipe runs under the axle on that side.
 
#17 ·
#20 ·
This is the NZ way of achieving the same result.
Are they trying to jump start it, perhaps? Can't see what having the hood open is going to accomplish. :)

But I see your NZ and raise you another OR.
Image

Same ocean, same human stupidity on respecting tide patterns. This time with something a lot more expensive (they did manage to pull it out, barely in time).
 
#22 ·
I have a 2009 Subaru Impreza 2.5i hatchback I keep getting the code p0028 which is my vvt solenoid bank 2 well Ive replaced it and I ve also replaced both oil pressure sensor and switch plus the oil sender I have changed the oil and filter oil level has been fine right where it needs to be at but I keep getting that code popping up I can clear the code but it always comes back on and I also get a burning smell and some smoke coming from under the motor on the driver's side I have also changed the value cover gasket as well anyone got any ideas
 
#23 ·
First,your engine may be on the way to crapping out. As in bearing damage. The continuos p0028 after replacing sole oids and oil switches means poor oil flow.

2nd, any smoke is probably an oil leak and your generation has issues with the single layer head gasket leaking oil and it drips down into the exhaust. The repair is pull the engine if it's that.

3rd, rear camshaft cap seal may be leaking. This seal is not in a head gasket set. It will also leak down onto the exhaust.