darkestskydiver

OK so i just got finished swapping out the engine in my 89 4runner. i put a new long block in it and swapped over the rest. i got it started today and it does nothing but smoke once it starts getting to operating temp. but at idle when clod or if it has been sitting for about 15-20 min it will not smoke until you give it gas or put a load on it. any one got any ideas? i took a short vid go HERE to see it. in the vid it is at idle after being warmed up.

Toyota_Pilot

sounds like a valve seal. once it gets warm it the seal expands opening a gap for it to drip into the cylinder. just a guess

darkestskydiver

ok so i tested a few components. the maf tested good the CSI tested good. i was able to pull the following codes: 12,41,43 and 52 going to test the tps next any other ideas?? oh and so far i have not noticed any change in the oil levels

darkestskydiver

well the TPS i believe tested bad. at idle i had 5.49 k ohm but at any other position the reading does not change i know at wot it should read between 3.1-12.1 k ohm. while my reading fell into that spec it did not change at all as i moved the throttle slowly.

myyota

When you had the head off did you have it checked out by a machine shop ?, or at the very least have the valve stem seals replaced ?. If not, thats probably why its smoking.

darkestskydiver

no this is a rebuilt longblock that was purchased so i assume they do all that at the factory

nothingbetter

Do you get a big puff of blue smoke on startup? That is a sign of bad valve stem seals.

What colour is the smoke? in the vid it looks white. White = coolant. black = fuel. blue = oil. Knowing that will help us trouble shoot.

abecedarian

What are you using for oil to break it in?

How's your PCV valve?

darkestskydiver

see thats the thing when i start it up cold there is no smoking at all its clean but once it heats up thats when it starts poring out the smoke. the oil is just your standard 10w30 i think it was the oriley brand. would a bad tps sensor cause those symptoms? the pcv valve is brand new but the hose does look rather cramped under there. i did leave the hose off to vent outside and pluged the port on the intake. there was no change.

darkestskydiver

would the knock sensor cause this? or maybe the wire or connection?

nothingbetter

Extremly unlikely that its a sensor. Somehow there is fluid entering your combustion chamber which is causing smoke. Likely a bad gasket or seal at some point.

As I posted above, once we know what colour the smoke is that will really help us narrow down where its coming from. I'm trying to help but I need more info!

darkestskydiver

I'm sorry i thought i put that in, from what i can tell it is defiantly blue but there are some hints of black here an there. how would i go about checking the valve seals?

nothingbetter

For future reference, I am not a mechanic. I could very well be wrong.

Blue smoke is oil. Smoking at start up is a key sign of vavle stem seals. When the engine sits overnight, oil slowly leaks past the stem seals and sit on the valve, when its turned over and fired up, valve opens, oil goes into the cylinder, the oil gets burnt causing an obvious puff of smoke a second or 2 after startup.

So, oil can enter the cylinder in a few ways. Through the air thats involved in combustion, valve stem seals, through the head gasket or past the rings.

Some oil is natural in the air as thats what your pcv (positive crankcase ventilation) system does. Its sucks fumes from the crankcase and forces them into the intake system so they get burnt. In those fumes is oil vapour which gets burnt. The amount of oil needed to cause that much smoke seems impossible to be coming through the pcv system. But crazier things have happened.

Valve stem seals, since there is no puff of smoke on start up I'd feel safe saying thats not your problem.

It seems backwards for it to be coming past the rings. When its hot, the rings have expanded and in theory create the best seal with the cylinder wall. Maybe they had a new guy who put it together and messed up the oil scraper ring install.

So that leaves head gasket. Which makes more sense than the rest of them. If your block/head is warped, it might seal well enough when cold, but when it heats up and expands, it causes a space for oil to get sucked into the system.

I'd check your plugs first and see what they look like. Run it untill it starts to smoke, let it run for another minute or so. Then pull them. Take pictures if you can. Lets see what they look like! This will let us know if we're dealing with one problem cyclinder, or a different issue.

nothingbetter

have you talked to the company you bought the long block from?

darkestskydiver

i have not talked to them yet i wanted to have a more solid case when calling. i will check the comp later and see if there is an issue with the head gaskets.

85TurboRunner

Have you drivin it yet?

darkestskydiver

i have driven it up the street and back to my house. at first it was fine no smoke just like when at idle. then when i got down the street and was turning around it started smoking real bad by the time i got back to my house it was pouring out like i had a fog machine out back. the truck seems to have decent power but it starts smoking and then the engine light comes on and it starts idling real rough.

85TurboRunner

I'd say contact the company you got it from like posted above. It should not be smoking like that and it definitely seems like an internal issue that you did not cause.

abecedarian

I mentioned the PCV valve for good reason-new / newly rebuilt engines will produce a fair amount of blowby and that will cause oil to be drawn into the intake and burned.

A modern oil is really not suitable for use during the break-in phase of our engines either due to the added use of "friction modifiers", low zinc content and such- you're trying to break in the engine so you need some friction here. If everything slides, there is no "break in" happening.

Whatever oil you're using, it should be rated no more than SF and CC. Using the cheapest oil on the shelf should get you near what you need.
But if you have to, use an oil rated for motorcycles with wet clutches.

nothingbetter

but having that much smoke from blow by alone? Sounds a bit exaggerated to me My friend used mobil 1 full synthetic for break in. It didn't noticeably smoke. Didn't last very long but thats regardless.

An easy way to check for that is pop off your intake manifold and see if its really oily inside.