Oil build up - mist - rear of plenum

[irox]

I've been noticing a build up of what appears to be oil blow-by on the rear of the plenum and I'm wondering if I should be concerned about the amount and/or the location.

Here are a couple photo's; sorry about the low quality, cell phone camera.

its a '98 V8 with 23K miles which I purchased June this year.

Car seems to run normal, good power, no codes, engine sounds smooth, rather like a "loud" sewing machine; no noticeable smoke from exhaust. I removed the oil filler cap and revved the engine while holding a paper strip over the filler pipe and the vacuum from the engine pulled the paper downward trying to ingest the strip, so I assume the crankcase is not pressurized. That's about all I have done to diagnose, other than steaming the engine clean and I'll keep a watch on it and see if it returns; which no doubt it will; but perhaps I can get a handle on from where its coming.

Does this look, sound typical? Should I be worried ? I'll have a compression and leakdown test done next week.

Thanks

Edited August 17, 2012 by irox

[irox]

And the air boxes are clean

[ESPREE]

I think the most likely candidate would be the oil line right there that goes to the turbo. Take a look at the diagram in this thread and look for the external tube on the right side (which is the end of the motor closest to the rear bumper):

Maybe also the oil gallery plugs that are at othe end of those long galleries.

If you clean up the oil and keep a close eye out you should be able to locate the source. A lot easier than the other side of the motor!

[Günter]

is there any 'blow by' on the MAP-sensor port (undo the sensor and inspect the hole in the plenum for its condition, was there something used (silicon) as replacement for an original sealing rubber?

inspect the turbo pipes to the plenum, how much oilbuild up is there in the pipes directly to andd from the turbos ?

..are the hose clips for the two ellbows that go into the plenum/throttle body-intake thight and is it all clean there ?

Is the intermediate layer alloy plate that sits between the red plenum section and the cast alloy ellbows sealed, or was there a gasket removed/sections separated one time ?

You have an US specified car, so was there ever the EGR system blocket, and if so ..is the intake port fully closed or is there any 'blow by' coming out from the plenum chamber ..?

note: the oil-feed for the LH-turbo, mentioned by Kent ( the diagram link), this is located on the LH-head, so it is not near to what you show us in your picture..

[irox]

Hi Gunter,

Those are great suggestions which I will follow up on.

MAP Sensor

Removed the sensor; there is what appears to be an OEM sealing rubber; orange multi-level, accordion looking thing... you can see it was partially split; pretty sure it came "out" that way.

The wall of the port was fairly clean; some grudge in the bottom (seat); I wiped it out with a qtip and also ran the other end of the qtip down inside the port to try to wipe a sample from inside (never have seen the inside) and could not reach anything solid. Did not loose the Tip of the Q; that was good. I would say it was not too bad; but, never have looked at one before; so, for 23K miles; look OK?

I'll have to remove the boot tub to gain access to the turbo in/out-lets... IAC and EGR... tomorrow.

Oh, and the gaskets between the layers (plenum/manifold/etc) are fitted and seem OK; looking at the outside edges only.

Thanks a lot for your help; you obviously have been "all over your Esprit"; probably completely disassembled and reassembled it a couple times; eh?

Edited August 18, 2012 by irox

[Günter]

the MAP-port looks like it was never touched before. sad to say ..but the build up must come from an other point near to the area of that. Don't worry, you can refit it, as long as the sealing on the sensor is in this condition, just add an amount of silicon sealing/adheasive there to the sides to help sealing.

to inspect the turbo-pipes comming from the turbos and going to the intake ellbows of the plenum means to verify how much oil is there in general, as a content within the air delivered to the intake. Several engines have shown notable oil build ups in the filter housings, simply by the fact that the crankase breather is routed to the air-filters there by factory (legal requirements)..and the cars of some owners have got a rerouting mod with 'open breathers', but that is a question of legality in your region/state.

The trunk/rear luggage compartement is a simple fibre construction -just use a 10mm spanner/wrench/socket for the engine cooling-water canister and the eight screws lower there on the floor of the trunk plate, a cross head screwdriver (for the two small phillips type screws there under the sides of the carped, left and right) those are still there on some cars as long as the previous owner/ the previous garage refitted them (facing to the vertical engine side of the trunk), and an allen key for the upper side next to the sidewalls of the body area.

If you have not much oil there in the filter housings, and therefore not much on the turbo intake-side ..but a lot of oil on the turbo 'compression-side' that goes up there to the plenum intake -your turbos are a point to look after.

From the only light amount of (dirt) or oil-build up on the outside it looks from what I can see only like a slightly not really thight connection on one or both of the hoses connecting the intake ellbows to the turbo pipes .. or at least that would be the simplest cause to work on -but I wounder that you say you have boost and it sounds all normall there.

you mentioned that there is no notable 'oil burn' comming from the exhaust ports under load changes ?.. -so it would also mean the amount of oil in your plenum intakes is based on that not more than on other engines from this type.

Oh, yes ..I know "some points" on those cars ..especially if you're more on the way to solve problems with 'household materials' it is good to know how things work. But that does not mean that you will never have to use real parts (have build up my 918engine up from the crank and on some areas, and used factory and 'non factory specific' parts on the engine and the whole car over the last 10 years)

as a future note: to remove the trunk floor helps a lot on working there on the engine, so you should not worry about , it is a simple job an makes things (as such -'to undo the plenum' ..for example if it comes to Idle-air-valve jobs ..or starter removal/refurbish) a lot easier. You can sit (stay) there on the gearbox and work directly on the engine, even if it is running

Edited August 18, 2012 by Günter

[irox]

I ran out of time today, took the Esprit into the tint shop for a 30 VLT tint job on side windows and that took a longer than expected

That boot floor is easy to remove and puts an entirely new perspective on things. As you said, you can just have a seat right on the gearbox; after wiping 23K miles of grundge. I did manage to see the turbo coupling hoses and I would say right away, I'm having some leakage from the right side turbo on the compression side. The hose clamp had a few turns left in the adjustment screws and I tightened them down, both turbos. I would like to remove them and swab a sample; but it looks difficult to remove the hose and fit it back. Is there a special technique or things to know before attacking it?

[irox]

Here's a shot of the entire engine bay; probably not very useful...

Edited August 19, 2012 by irox

[irox]

I have clear access to the turbo charge pipes; problem I'm anticipating is the pipe coming from the turbo is obviously metal, ie rigid, and I'm assuming the pipe is rigidly mounted which means no flex to the pipe; the hose is about 3" long, so limited flex there; and of course the short pipe leading into the plenum is rigid. So, how easy is it to remove the hose with no "give" (deflection)? Do I loosen both clamps and slide the hose left or right? Seems unlikely.... Do I need to loosen the mount on the pipe coming from the turbo? Or, forbid, remove the plenum?

[irox]

The intake passage of the IAC looks very clean, I even crimped a paper towel wad on a "claw", inserted it into the aperture, swirled it around and it came out with a yellow orange sport or two. No blackness, smudge whatsoever.

I'm sort of scratching my head over this at the moment. I'm thinking nothing is out of sorts with the turbo. I'll keep digging

I also ran a dewalt remote camera inside the port. Looks ok

[irox]

Progress, I think

I ran my finger behind and upwards on the right side turbo hose connecting to the plenum elbow. It was wet with oil; not dripping; but definitely wet. The opposite, left turbo, was not; So, as my previous images suggested; the right side coupling seems to be the culprit; as also previously mentioned, the hose clamp was not loose; but there were turns available on the adjustments screws and I did tighten it up. So, question is, is it possible it was just a loose hose; but I have to wonder from where the oil is coming, loose hose or not; Is there anything significant behind that hose that could be leaking (dripping) on the backside of the hose.

Need better pictures of what's behind there...

Although, I feel as if I'm on the trail of the source

Edited August 19, 2012 by irox

[fastdave92649]

Could be the turbo seals going bad causing oil to seep into your intake track. Might be time for a rebuild of that turbo. Nothing behind that hose to drip unless your block is cracked. Take the right pipe off and look inside for excesive oil in it.

[Günter]

the cast alloy turbo pipes are just screwd onto the engine, use a 13mm hex spanner/wrench/socket .. nothing with 'space age technology' there ..to undo the turbo(s) is also possible with engine in ...but needs some more time and a place where you can use a sort of Dremel/Proxon/De-Walt minigrinder sort of thing.. to simply cut off those odd and mostly rotten nutsholding the turbo onto the exhaust manifold (head side) .. the three studa to the catalyst simply shear off in case of rusty conditions ..you can drill out the remains later on. if you undo the requested turbo fabrikate your own 'special tool' made from 'oldish' rusty spanners, as the space available there for the water pipe couplings is not much .. top to bottom is oil feed/return , side to side is water cooling for the main section (as the Garrett turbos used are water cooled) -if you have the time to drive the car (or at least 'let ithe engine run' ) now .. undo the small breather pipes coupled to the air cleaner boxes. reroute every pipe into a can or clear bottle, so that you can verify that there is not much oil 'mist'/ vapour comming out from the breather (aka engine does have not much oil blow-by in fact) .. but anyway, you said that the 'fresh intake' side of that suspicous turbo is cleaner than the 'compression' side ..so the sighns are somewhat clear ..hmmm .. :-/