Question about my motor.

I have a 1996 legacy wagon which I purchased from my mother. The car has sat for a long time but surpisingly still cranks and runs like a champ!
The issue I am having as of late is the motor turns over without compression but the compression builds up on it once I sit there and continue to crank it and it builds up compression.

It will run a little ragged at first but after 2 mins of it running it smooths out and runs like a champ. I have my theories on the matter but I wanted to know what you all thought. Thank you.

If it has sat for a long time, have you put new fuel in? Fuel will break down after a while if it hasn't been used.

Also, a good tune up will help such as oil, plugs...etc.

I am actually going to do that tomorrow and do an oil change, new plugs, wires, flush the radiator, flush the engine and flush the gas tank out. The theory I have is the lifters are getting stuck open due to it sitting so long so the oil has a build up on it. I could be wrong lol!

Possible. After you do that, let it warm up good before driving it, to make sure everything gets lubed on the inside. Good luck

Thank you very much. What would you think it could be if none of that helps? Once the engine warms up there is no knocking or anything so there are no signs of bent rod or anything like that.

If it still has problems starting, I would recommend doing a compression test to see if the cylinders are holding pressure.

You need to do a compression check

Originally Posted by broknindarkagain

You need to do a compression check

Beat you by a second.

Originally Posted by F1inspiredLGT

Beat you by a second.

ROFL!

Well lets hope all the work I do fixes it. The car only has 143k miles and it even says on the title that the actual miles are 143k. Thank you all for the input and will keep you informed.

new subaru plug wires or HIGH QUALITY replacements.
new NGK plugs.
fresh fuel, but if it smooths out after it runs for a while it probably isn't the fuel. fuel would still be iffy.
when you change the oil add a pint of MMO to the oil this will help loosen any crud in / on / around the HLAs, lash adjusters. these can get gummed up.t hen change the oil again in a couple of hundred miles.

let it idle for 30 - 40 minutes. and then drive it.

once you start driving it and get all the old fluids out it will improve. (assuming it was running ok when it was parked.) they usually do not go bad when sitting. at least nothing major.

it is a great engine. enjoy it.

And don't go thrashing it too soon, sitting oil seals tend to shrink and need fuel in and around them before they swell up again. You don't want to blow a main engine seal on yer maiden voyage.

If you do decide to take johneggs advice on the Marvels Mystery Oil, get another bottle and put it in your gas at roughtly 1.5x to 2x the dosage recommended on the bottle for the first couple tanks then reduce to the recommended dosage on the bottle till its gone. If you have a vehicle that sat, it lubes/cleans the injectors and removes deposits.

I had a very dramatic improvement on my Jeep after using it... Jeep sat for maybe a decade and I did tons of work to it... the MMO helped make all that work worth it.

Originally Posted by johnegg

new subaru plug wires or HIGH QUALITY replacements.
new NGK plugs.
fresh fuel, but if it smooths out after it runs for a while it probably isn't the fuel. fuel would still be iffy.
when you change the oil add a pint of MMO to the oil this will help loosen any crud in / on / around the HLAs, lash adjusters. these can get gummed up.t hen change the oil again in a couple of hundred miles.

let it idle for 30 - 40 minutes. and then drive it.

once you start driving it and get all the old fluids out it will improve. (assuming it was running ok when it was parked.) they usually do not go bad when sitting. at least nothing major.

it is a great engine. enjoy it.

Yeah the car runs great after it warms up. No knocks, sputters, stalls, etc. AWD works great, tranny does as well. No leaks at all period. The inner tie rod on the rack needs to be replaced but that is not hard. PRetty solid car for it sitting for soooooooo long. I shall take all of you lots advice and see how this pans out. Will let you know Thank you!

Originally Posted by pqkillerAU

And don't go thrashing it too soon, sitting oil seals tend to shrink and need fuel in and around them before they swell up again. You don't want to blow a main engine seal on yer maiden voyage.

No problem there I shall most definitely take it easy on the car for a while.

Ok just a little update for you all. The replacement parts and fluid change plus driving it a lot has solved the no compression at cold start problem. I will be changing the oil and filter soon to make sure all the crude is out of it the best I can besides taking the motor apart.

With that said I have ran into a new problem >.> I let my sister borrow the car because her's is in the shop and she has kids. When I got the car back the gas gauge was slap on "E" so I figured I would wait until tomorrow to go gas it up before work since it was really late when I got the car back. She drove it there no problem but when I went to go start it the next morning I got no fuel to the engine. I shot some starter fluid in the intake itself after the MAF, (I know better) and it fired right up no problems. I checked the line going to the fuel filter, nothing, I checked the pump itself and it works, comes on and everything. I did notice that when I took the lines off at the fuel pump itself that nothing was coming out at all. My thoughts on it is the tank was ran so low the strainer sucked up all the garbage on the bottom which has clogged it. I am out of town currently so I have not been able to confirm that thought. What are you all's thoughts on it?