‘00 5.9 Smokes a lot

[Kevin Breaux]

Hi guys first time posting. Got a 5.9 ram 225,000 miles used about a month ago . Drove it 2.5 hours home ran great .few weeks later Changed oil put in synthetic 10w40 now smokes a lot first thing not on start up but driving down the road for a few miles losing about a quart in 75 miles . Read a lot of posts on here about plenum . I did the vacuum test as well as looked down tb .no Vac. No oil . Next went on to compression test all pretty low about 85 . Wet test 140 . I can tell rings are wore out but wasn’t smoking before .?? Smoke is grayish . Any thoughts ?i immediately changed to conventional 20-50 same thick smoke. No water in oil or in radiator that I can tell .

 

[Nick_rp]

Gray smoke while driving is either valve stem seal or piston rings. Smoke while accelerating is piston rings, smoke while deceleration is valve seal

When you changed the oil it was most likely a thinner viscosity than what was in there. Previous owner probably knew they had bad seals and added thicker oil to mask the bad seals/rings so they could sell it easier

 

[pacofortacos]

Most common is the intake manifold plenum gasket - pull the air cleaner off of the throttle body and with the engine off, manually open the throttle to wide open throttle and look down into the throttle body with a good flashlight - if you see puddling oil that is your problem.

 

[ViolentMouse]

Did you say a quart of oil in 75 miles?

I don't know how that could not be eating oil through the PCV or the plenum... I mean, I'm sure your rings are shot and your valve guides and seals are probably just as bad, but a quart in 75 miles..... that's almost a full oil change every tank of gas.

I would put a clear hose on the PCV with a loop in it and see if it fills with oil....If you have bad enough blow by that seems the only logical way to shove that much oil into the cylinders, but your plenum should be nice and wet with oil. You should take a photo of your plenum for us

 

[Kevin Breaux]

Did you say a quart of oil in 75 miles?

I don't know how that could not be eating oil through the PCV or the plenum... I mean, I'm sure your rings are shot and your valve guides and seals are probably just as bad, but a quart in 75 miles..... that's almost a full oil change every tank of gas.

I would put a clear hose on the PCV with a loop in it and see if it fills with oil....If you have bad enough blow by that seems the only logical way to shove that much oil into the cylinders, but your plenum should be nice and wet with oil. You should take a photo of your plenum for us

. Still no oil on plenum . Put the clear hose ran across town and back no oil in it either . Changed pcv valve also . This one has me stumped .

 

[Kevin Breaux]

Thank you all for your time in helping me figure this one out ! Can’t wrap my head around it . Just from changing oil went to choo choo train . Like I said my compression was around 85 dry and 140 ish wet across all cylinders which is bad ,I know but it really smokes after it sets awhile but after a few miles it nearly all goes away . Unless I stomp on it . Seem like a lot of oil consumption to me for only wore rings . And never smoked before I changed the oil. Still has full power runs like a champ otherwise.

 

[Kevin Breaux]

I removed the plugs in order . Maybe it’ll help having more information. I pulled of passenger side valve cover and it looked really really clean . No broken rubber laying around . Seals looked pretty tight on valve stem . Stem was shiny where the oil was wiped clean. No obstruction in oil tubes.

 

[pacofortacos]

A couple of the plugs look fairly wet but still that is a lot of oil.

Any leaks? Esp. around the oil filter, I have seen the old oil filter gasket stick to the engine and it is easy to miss if it happens.

 

[Kevin Breaux]

A couple of the plugs look fairly wet but still that is a lot of oil.

Any leaks? Esp. around the oil filter, I have seen the old oil filter gasket stick to the engine and it is easy to miss if it happens.

. Little wet around pan gasket but not dripping or leaving puddles behind . I’m sure it’s leaking some. Just tried to post a short video cold start idle and no evidence of smoke .just walked and double checked old oil filter and gasket was stuck on it . Thanks for the caution.

 

[Kevin Breaux]

Read about putting the magnet down to see if it’s been updated with the Hughes aluminum pan. Stuck my magnet down throttle body and it stuck to it. I’m wondering if since I just changed the oil I can’t see it on plenum. Thinking of just pulling intake so I know for sure. Wouldn’t bad plenum smoke more on idle though since that’s when vacuum is present ? It don’t smoke at all at idle even cold start . Smoke starts on first acceleration for a few miles then once it’s warmed up smoke goes away. Any body have these symptoms from plenum failure?

 

[Kevin Breaux]

quick video of startup after sitting all day . No smoke . But if I take off it’ll bellow smoke until engine warms up then it’s gone . I don’t get it.

 

[Kevin Breaux]

Did you say a quart of oil in 75 miles?

I don't know how that could not be eating oil through the PCV or the plenum... I mean, I'm sure your rings are shot and your valve guides and seals are probably just as bad, but a quart in 75 miles..... that's almost a full oil change every tank of gas.

I would put a clear hose on the PCV with a loop in it and see if it fills with oil....If you have bad enough blow by that seems the only logical way to shove that much oil into the cylinders, but your plenum should be nice and wet with oil. You should take a photo of your plenum for us

Ah ha so pulled throttle body off now I see oil pooling at the back . This must mean it’s bad correct?

 

[pacofortacos]

That actually looks incredibly clean in there, does it look like the intake has been off before?

Or is it just the picture?

At idle you have high vacuum in the intake, but you really don't have much oil flying around under the plenum and not much air flow in the manifold to lift the oil to the cylinders.

At higher rpms you have both of those things happening and really high vac. on decel.

It could just be a piston with the rings worn/stuck too that would cause it smoke under load.

I will be honest though, the engine at those miles will need rebuilt and new heads if you want to fix the low compression issue. May be as little as a re-ring job and new heads but plan on cylinder heads either way if you tear into it.

 

[Kevin Breaux]

That actually looks incredibly clean in there, does it look like the intake has been off before?

Or is it just the picture?

At idle you have high vacuum in the intake, but you really don't have much oil flying around under the plenum and not much air flow in the manifold to lift the oil to the cylinders.

At higher rpms you have both of those things happening and really high vac. on decel.

It could just be a piston with the rings worn/stuck too that would cause it smoke under load.

I will be honest though, the engine at those miles will need rebuilt and new heads if you want to fix the low compression issue. May be as little as a re-ring job and new heads but plan on cylinder heads either way if you tear into it.

That actually looks incredibly clean in there, does it look like the intake has been off before?

Or is it just the picture?

At idle you have high vacuum in the intake, but you really don't have much oil flying around under the plenum and not much air flow in the manifold to lift the oil to the cylinders.

At higher rpms you have both of those things happening and really high vac. on decel.

It could just be a piston with the rings worn/stuck too that would cause it smoke under load.

I will be honest though, the engine at those miles will need rebuilt and new heads if you want to fix the low compression issue. May be as little as a re-ring job and new heads but plan on cylinder heads either way if you tear into it.

got intake out don’t see a visible failure of gasket

 

[Kevin Breaux]

Might as well put new valve seals while I got some room maybe it’ll help. Thank you guys for the help! I did a thorough compression test I don’t know why it differed from the first . Started a thread for that but no reply’s .But with ign. Fuel disconnected .completely warm engine. 6 sec. cyl. Throttle wide open. And for wet 3 squirts from oil can . Spec says 100 psi is min. I think rings would last a bit longer . I hope.

 

[pacofortacos]

Did you take the pan off of the intake? You might see a failure then if you hadn't.
Before replacing the gasket, run the bolts in without the pan on and see if you have enough depth for the bolt to go the whole way in.
Supposedly, some of the holes were tapped shallow and that is why the gaskets failed.

 

[Kevin Breaux]

Did you take the pan off of the intake? You might see a failure then if you hadn't.yea I pulled it off already , didn’t see much wrong but ,great tip gonna check that now.
Before replacing the gasket, run the bolts in without the pan on and see if you have enough depth for the bolt to go the whole way in.
Supposedly, some of the holes were tapped shallow and that is why the gaskets failed.

 

[Bulwinkle]

Agree with Nick_rp:

Begin-at-the-beginning: no smoke when purchased, smoke with 10-30w synthetic. Simple test is to change oil to straight 30W as a test or put in STP oil treatment to thicken oil. Theory that seller thickened oil sufficiently to stop severe oil consumption they knew was occurring. If a certified tech did this test for you, it would prove that the former owner knew this was a pre-existing conditioning when they sold the truck to you and may give you a chance to force a refund of the purchase.

 

[ViolentMouse]

That wasn't an "excessive" amount of oil on the plenum, but it is 100% drawing oil in through either the PCV or the breather. I expect some oil in those plenums as they have no way to get rid of any oil that goes into them.

Based on the quart per 70 miles you defined I would have expected at least half of that to be sitting in the plenum pan.

Since you have it off, get a hughes plenum pan, it won't hurt and can only be better than the stock one.

around 100psi is low compression....for example, my weakest cylinder on my motor before it failed was 138.

I suspect the rings have seen better days. If you plan on pulling the heads, a quick test is to rotate the motor so that all pistons are below the deck and fill them all with ATF. If any of them drain all of the ATF overnight.... bad rings... re-ring it, and then since you have the heads off.... pop for a set of those nice edelbrock alu. heads, or even some of the EQ cast heads (harder and harder to get.)

 

[ViolentMouse]

I just notices the photo of your plenum pan.... do you see all that oil sludge on it?

100% your oil control rings... are filled with that.

you can try seafoam treatment, or you can just re-ring it.... my suggestion....if you are going to go as far as a re-ring...just have the motor rebuilt. it will provide many more years of reliable service, and the motor will probably outlive the rest of the truck at that point lol.