Time for a new engine or rebuild??

okay here I go...
I have a 1995.5 Tacoma 4x4, 2.7, with 201,500. About 500 miles ago I decided to straight pipe the truck since it felt like it started running restricted after I seafoamed it. Well I recently noticed that my truck is burning more oil than normal for its age. It would usually burn about a quart every 5,000 miles and it has a slight leak around the oil pan but its not bad enough to drip on my driveway. I am about 1,500 miles into a fresh oil change with castrol 5w-30 part synthetic and I just checked my oil and it is reading half full on the dipstick. (I meant to switch the truck to full synthetic at 200k but I bought part synthetic on accident and was too lazy to return it so I ran with it.) Anyways, the engine seems to be running fine with no abnormal noises so I am starting to believe that there are 3 things that could be causing my issues: 1. straight piping the truck fucked something up. 2. switching from regular oil to part synthetic fucked something up. 3. the truck has just seen too many miles and it either needs a new engine or a rebuild. What do you guys think I should do or the cause of my new issue is? I am stumped since I have limited knowledge on engines.

 

Removing the catalytic converters took away a good bit of needed back pressure.....that could have something to do with it. I've never put synthetic in anything with more than 10k miles so i don't know anything about doing it at that late of an age.

I would rebuild an exhaust for it and scower the whole block to look for traces of leaks or problems.

Is the truck running any hotter than normal?

Also, that engine should be able to go another 50-100k milesif maintained well

 

Sorry for not being clear, I left the cats alone all I did was chop the muffler. But when the sun is up tomorrow I will take a better look around the engine to check for new leaks. And from reading various threads I understood that running synthetic at high mileage would not harm anything. The truck is not running hot at all.

 

If the cats are still there, then that shouldn't be an issue....people may debate that there is a little bit of low end torque loss from no exhaust after the cats but some people would rather have the sound...so, who cares?

I'd just pull a plug while looking the block over and check it for smells of burnt oil. If it smells pretty plain and like burnt fuel, then that is fine and it is possibly something else....

 

I plan on doing a compression test tomorrow and will check for odd smells as well.

 

Sounds like a plan. Hope you find an simple, easy to fix, answer. I can't believe no one else has commented....

 

First gen problems.


You'll get her beat!

 

I switched to synth in the same truck as yours after 150k, engine ran a lot smoother and seemed to be a little stronger.

The amount "disappearing" is disconcerting, but Toyota does allow for a certain amount (can't remember how much, but there's a thread on TW). Three choices here- it's going somewhere (leaking head gasket, cracked block?), it's burning (you should see an increase in blue smoke out the tailpipe), or on the ground. Check the coolant. Compression test is a good way to go.

That little motor will do 300k. Looking forward to your findings.

 

It's an old wive's tale that you cant put synthetic oil in an older engine with as many miles as yours...I convert my vehicles to synthetic all the time. IF they vehicle did not receive regular oil changes prior to conversion to synthetic then you could have problems...but the problems would not be due to the synthetic oil.

Unless you are burning excessive oil, I would NOT worry about it too much. Just keep an eye on the oil level and add oil when necessary.

Up to 1 quart per 1000 miles or so oil consumption would still be ok. Much cheaper to add some oil once in a while than to rebuild the engine.

 

I appreciate all of the replies. It looks like I am just retarded though because when I checked the oil the truck was on slightly uneven ground which ended up throwing the dipstick reading off by a quart in a half. I ended up adding half a quart and now its completely full. I never got around to doing a compression test but eventually I will. The truck is running great though so I think I will be okay for hopefully another 100,000 miles.

 

Hey, good on you for being proactive. I wish I had never sold my 95. Good luck!

 

Do you happen to see dynos showing that "backpressure" increases power? Maybe a narrower exhaust passage could improve scavenging, i.e. the exhaust expanding as it goes out, helping to suck exhaust out of the head...but the 2GR V6 goes from 276 flywheel hp to about 300rwhp with headers and exhaust. That's the opposite of backpressure.