S148 from Turbo Technics

[CalMac]

Haven't driven the car for a while now because this has p*ssed me off and I'm worried it's something serious which I don't want to exacerbate. Emailed a couple of MR2 specialists asking to bring the car in for a check over but they didn't bother replying

There was oil in the intake side of the turbo, so I'm hoping I may just be getting excessive blow-by from the crank case.

Can anybody recommend a decent catch can to replace my standard one as it doesn't appear to be doing the job?

It doesn't look like Fensport still make them, and the eBay specials all have undersized inlet/outlet bores from what I've been reading.

If that doesn't solve it then the turbo oil return will have to come off to check for blockages, which I really can't be bothered to do at this point.

And if it ain't that then either the turbo is goosed (wonderful. TT will claim it was something I did wrong) or the engine is fooked - equally wonderful.

[jimGTS]

Don't waste money on a catch can, stock one is decent.

I suggest fitting a breather to the oem one, or just routing it to the floor (what I do), and blocking up intake hole.
That way you can rule out crankcase gases at least and costs you very little to nothing as opposed to fitting a restrictive crappy eBay catchcan.

I suspect poor rebuild of turbo.
You literally went from no issues to installing this and seeing smoke no?

[CalMac]

That was my plan initially but I'd read that it was necessary to create a vacuum between the intake to help draw air out of the crankcase. But if I can just leave it open then I'll try that

Yeah started it first time after the rebuild and it was smoking at idle, don't think it was smoking when it idled with the knackered ct20b.. I wont have a leg to stand on though - they have too many get-outs to bother reimbursing me if it does turn out to be the turbo.

It's not burning HUGE amounts but sometimes when I come to a stop a cloud of exhaust smoke will waft past me, I still get puffs on overrun and it's noticeable on the dipstick (which is worrying for a car I drive about twice a month)

[SonicSW20]

Could get one of these - https://www.ebay.co.uk/itm/IP67-5-5mm-6 ... 2985439902

Remove O2 sensor, you'll be able to see the turbo outlet and see if it looks like it's leaking there?

If it's pushing enough oil through crank case to smoke then just disconnect the vent to intake hose - if it stops you know it's that.

[CalMac]

I might have to invest if the hose re-route doesn't work!

Is it something to worry about if a significant amount of oil is being kicked out from the crankcase breather? I figured it might just be because of a slightly bigger turbo and therefore more pressure..? That may just be daft reasoning though.

[CalMac]

Had the intake pipes off again Saturday morning and cleared the newly deposited gunge from the turbo inlet and hoses, then used a can for a temporary catch can (which I plumbed the hose coming out of the standard catch can into) and blanked off the hose input to the air intake pipe.

After 100 miles there's no oil in the catch can, maybe a drip or two. But the car is still smoking and stinking

So maybe it's time for me to get one of these endoscope cameras..

If the turbo seal is fooked, is it likely that TT supplied it faulty? Or will I likely just be lumped with another bill to repair the turbo?

[SonicSW20]

Did you get to the bottom of this?

If it was smoking from the off and you are 100% certain you do not have any issues with oil feed and drain and oil contamination, then they should sort it. A blocked or partially blocked drain will cause excess pressure in the turbo, and the oil will force its way out elsehwere. Easy way to check - disconnect the drain at the sump, start the engine and confirm there's oil flowing out of the drain.

It's possible the IC still has a fair bit of oil in it if the old turbo chucked a lot of oil into the intake side. It can take a while for that to be pushed through.

[CalMac]

It's still being problematic! I've been going through things today trying to get to the bottom of it. Still smoking, still burning some oil and using a LOT of fuel.

However I'm still getting decent performance.

I get what sounds like a squealing/whining under boost which I thought was either a vac leak or boost leak from one of the hard pipes. And yesterday it was refusing to boost over 1.2 bar for some reason, despite the parameters on the boost controller limiting boost to 1.3 bar and it usually performing well.

My theory now is that the ECU doesn't like the new turbo and is overfueling - causing bore wash and burning the oil. This could be as a result of dodgy O2 sensor too I guess? Or vacuum leak.

• The turbo inlet is pretty clean now since I re-routed the OEM catch can into a temporary can, but still the problems persist. The turbo outlet and hot pipe are quite mucky though with thick carbon soot. I've also had the intercooler out and the inlet side at the bottom has a fair bit of carbon buildup - the top outlet side is relatively clean. Throttle body is clean.

• The O2 sensor was quite loose (two bolts holding it on) - pretty much hand tight.

• No noticeable increase in shaft play on the turbo.

• Still only notice the smoking when either: On overrun for more than a few seconds, especially when going downhill; when idling at traffic lights etc. for 10s+ and then revving it will puff out smoke; or approaching a junction and then coming to a stop a cloud of blue/grey smoke will waft past.

• I've not noticed any significant smoking under load or between gear shifts (basically while hooning) - with the help of a mate driving behind.

Personally I don't think it's the turbo oil seals. Borrowed a borescope and stuck that in the O2 sensor port earlier but couldn't really see anything to be honest. The whining and excessive fuel usage are leading me to believe that overfueling is the issue due to boost/exhaust leak somewhere. I've left the battery disconnected overnight so will see if the ECU has cleared tomorrow - would be nice if it was that simple!

From what I've been reading a dodgy O2 sensor won't show up when checking for fault codes?

[SonicSW20]

My theory now is that the ECU doesn't like the new turbo and is overfueling - causing bore wash and burning the oil. This could be as a result of dodgy O2 sensor too I guess? Or vacuum leak.

Stock ECU? You can test the o2 sensor and read long term fuel trim at the diag port.

Multimeter in DC Voltage mode. Engine fully warmed up, test at ~2500RPM.

E1 - OX1 - https://www.youtube.com/watch?v=A-VBpBqPFiE
This is the 'raw' O2 sensor output. You should see it oscillating between ~0.1V and 0.9V or there abouts. It should fluctuate at around 1Hz. Workshop manual states 0.8Hz (8 times per 10 seconds) or higher.

E1 - VF1 diag mode - https://www.youtube.com/watch?v=TsqcKiNnqIw
Note it's in diag mode (E1 TE1 bridged). This is the 'ECU processed' O2 sensor signal, it should flip between 0 and 5V at the same rate.

E1 - VF1 no diag mode - https://www.youtube.com/watch?v=lwXTR1qMoEg
This is your long term fuel trim. 2.5V = it's running perfect as far as the ECU is concerned. http://alflash.com.ua/vf1.htm

My car with the same turbo does run rich, but I'm not sure it's any richer than any other Gen3 Turbo. AFR gauge install to complete will confirm I guess. I do have a bit of oil consumption but it's not excessive, and post rebuild there is no smoke.

• The O2 sensor was quite loose (two bolts holding it on) - pretty much hand tight.

If it was loose enough to allow air in / gas out, that would affect the O2 sensor reading and therefore fuelling.

• Still only notice the smoking when either: On overrun for more than a few seconds, especially when going downhill; when idling at traffic lights etc. for 10s+ and then revving it will puff out smoke; or approaching a junction and then coming to a stop a cloud of blue/grey smoke will waft past.

• I've not noticed any significant smoking under load or between gear shifts (basically while hooning) - with the help of a mate driving behind.

That sounds a lot like what mine was pre rebuild

Personally I don't think it's the turbo oil seals. Borrowed a borescope and stuck that in the O2 sensor port earlier but couldn't really see anything to be honest. The whining and excessive fuel usage are leading me to believe that overfueling is the issue due to boost/exhaust leak somewhere. I've left the battery disconnected overnight so will see if the ECU has cleared tomorrow - would be nice if it was that simple!

From what I've been reading a dodgy O2 sensor won't show up when checking for fault codes?

Depends what the fault is! But yes, they can fail in a manner that does not trigger a code. The tests above would be definitive on that front.

ECU reset only requires removing the EFI fuse for 10 minutes or so

Got to work through methodically and rule everything out of course, but it does sound an awful lot like typical turbo seal failure with the smoking on overrun, smoking after sitting idling etc. If it walks like a duck, quacks like a duck...

Have you checked your oil drain is 100% OK?

[CalMac]

Thanks for the detailed reply mate!

It's a stock ECU but looks ‘modified' I'll take a pic tomorrow - the face plate is spaced off for some reason. I've never touched it as it always just worked. Just dawned on me that this could be causing the issues, if it has been adapted in some way to perform specifically with the CT20b.. hmm.

I wonder if sticking a CT20b back on would solve all my problems. At the end of the day I've only had problems since getting the S148 fitted - even when the CT20b was knackered it wasn't smoking. Just made the horrible knocking/clattering sounds as (I presume) the exhaust side ate itself. I'd imagine that if parts of it went through the head back then it wouldn't still be running as smoothly as it is.

I'm supposed to be getting a leak down and compression test done on Friday anyway - if they turn out alright then it's likely to be the turbo oil seals I guess? And it'll be nice to know that the engine is ok! Fingers crossed.

I've tightened the O2 sensor up and washed out the intercooler - will stick everything back together tomorrow - will check the oil return while I'm at it but it'll be quite long-winded as the car has an external oil cooler.

Cheers for your help and patience

[Ryan S]

squealing under boost sounds like a burst exhaust manifold gasket. I had the same sound (almost like a shrieking) when my manifold explainable came loose. Would deffo explain any loss of boost at least.

[CalMac]

I've tightened the manifold and turbo to DP/adapter block bolts all up - some were a bit looser than I'd have done them but not massively.

Put it all back together making extra sure that there was no capability for leaks in the hardpipes or vacuum lines, and started her up.

Haven't been for a drive yet but found that it's just chugging out blue oil smoke if sustained at 4k+ revs - maybe this coincides with the boost threshold and could be the turbo seals?

Otherwise just idling or revving below 4k no smoke at all.

Also here are pics of my ECU (can't get them to rotate) - never taken the cover off before. Looks like some kind of piggyback. Might just buy another ECU if I can find one and then sell it again if it doesn't fix the problem? I have a feeling it's an aftermarket chip which has been adjusted to run a different AFR, rev limit etc. but of course optimised for the CT20B - which I would expect can cause quite a few issues when paired with a different turbo?





The bigger chip says:
D151803-9651
5A41C-2-8288
JAPAN 4J1003

The smaller one:
TMS JL
27C256-12
BLU82ZBKL8
THAILAND

The square chip has numbers etc. scrubbed off

[SonicSW20]

Looks very similar:
https://www.mr2oc.com/61-3sgte-turbo/45 ... efore.html

[CalMac]

Yeah I was just reading that! I think I'm going to buy a standard ECU and see what happens. As I said last night this problem has arisen since the moment the engine was started with the S148 so it's very likely to be either the turbo or ECU right?

[jimGTS]

id still say turbo seals

[SonicSW20]

Indeed, the symptoms do sound an awful lot like it.

Recently there was a chap on the Facebook groups who had a turbo rebuilt, installed it and it smoked like a Victorian factory. Sent it back and it turned out they had used the wrong spec seals! Annoying for the guy but the company fixed it and as far as I know it's been fine since.

[CalMac]

We shall see (where's the popcorn emoji when you need it)

FWIW I confirmed again this morning with the mechanic who fitted my turbo that he cleaned out the return line etc. and he was absolutely adamant that he did and that it wasn't particularly gunged up!

Picking up a standard ECU tomorrow, leak down test is happening today - so if it's still problematic then it's time to whip that damn turbo off

The car is on Ebay - just want to clarify that I won't be selling until this is fixed, I've just knuckled down the last couple of days and had some time off work to make sure that I find the culprit and rectify it before someone comes to test drive etc. as I'm not the type to knowingly sell a lemon on to somebody 'sold as seen'. If it's the turbo at fault then I'll just have to go back to TT and see what they say - really not expecting them to fix FOC though.

[CalMac]

Fitted another ECU yesterday and went for a 20 mile drive in the evening - didn't notice AS much smoke but it did definitely smell quite a bit when sat at lights etc. And when I got back held the revs at 4k to find that it still chugs blue smoke at higher rpm.

It's still performing faultlessly though drives really nicely - and bloody quick! Haven't seen smoke in my mirror when hoofing it or between shifts, or even on overrun/downhill etc. as before. Maybe the ECU has done the trick and I'm finally burning off residual oil?

I took a photo of the oil level on dipstick when changing the ECU anyway so will compare photos at the end of the week after I've hopefully had time to go for a drive.

If it is the turbo seals that have failed then I still need to find a cause for the excessive fuel usage!

Having looked on Turbo Technics website they don't offer any warranty on hybrid turbo units, so looks like I'm screwed even if it is the turbo

Spoke to a chap I know who works there earlier to see if he could give me any ideas how to approach TT with regards to a rebuild and he said: 'it doesn't sound like a turbo fault to be honest, if it was it would smoke all the time, it sounds like it might be breather related'.

I'd have thought that the smoking at 4k would coincide with boost threshold and perhaps point to it but I don't really know. I had believed that if turbo seals had gone then a car should smoke all the time though

[SonicSW20]

Turbo Technics can write whatever they want on their website, that doesn't absolve them of their obligations under CRA2015 - if it was faulty upon arrival then they have to fix or refund. Of course if the problem was caused by installation, poor oiling etc then it's not their problem.

Breathers / PCV are easily checked, make sure they aren't blocked and the PCV valve is operating correctly, not much else to the system really.

Might be worth taking the bottom IC hose off from underneath and seeing if there's any oil pooled up in the intercooler? Perhaps it was just oil left in the intake and / or exhaust that hadn't burned off / been pushed through? Seeing as it seems to be reducing with time run that seems to add up.

[CalMac]

I THINK that it might be ok now.

Let it warm up earlier and then revved it a bit - a few puffs of smoke when just revving it up a bit but nothing when sustaining revs at any point. Then nipped down to Northampton Motorsport to book it for a geo setup tomorrow as I had the wheel bearing replaced on Friday - it seeeeriously pulls now, running about 1.25 bar. Generally feels a lot happier on this ECU and since I've had all the IC pipes off etc. and made sure that there's no boost leaks.

Checked the breathers and PCV valve earlier and they seemed to be all good.

Definitely not noticing as much smoke now that the ECU has been swapped over. Going to have to put a few more miles on before I'm able to determine if the oil level has gone down, but I'm hopeful that the occasional oil smell I'm still getting is just residual

Still using a lot of fuel but am thinking that could be down to combo of my heavy right foot combined with the novelty of a relatively new-to-me amount of power!

And I had the IC out last week and flushed it all out with detergent, hot water etc. - there was no oil in the bottom, just thick carbon deposit.

Fingers crossed - will see what's happening in a few days I suppose. If it hasn't burned any oil then I'll be absolutely over the moon!