Hello all,

You may remember my post before, when the MAF sensor failed (apparently) on my MY00 PPP and it detted to destruction - piston #3 lost chunks of itself and the others were not looking good.

Anyway, I've had a complete engine rebuild with a new short engine and lots of other parts (including MAF sensor ) and the end result is not so good. I'm running it in, of course, at the moment, but even so the pick up is slow, and it won't make more than 5-7psi boost (which it struggles to reach). I'm only using max 1/3rd pedal travel and 3500rpm max, but before, it would hit 15-17psi easily under these circumstances .

Also, the oil temperatures are STILL high (around 115C!! ). KnockLink shows no problems, but was fitted after the new engine was fitted, so I can't be 100% sure on calibration (set to maximum sensitivity though).

Any suggestions? I want to check the fuelling system, and intercooler pipework in case of air leaks/split hoses etc, but all other ideas and suggestions are greatly appreciated Oil pressure looks good, holding around 100psi in running, dropping to 60psi on idle. Running 10W40 as running it in, therefore a little higher than normal 5W30.

Help!

(John Felstead: thanks for all the help so far... I'm just putting it open to the floor as well.)

Richard

ps I'll post pics on here soon, once I've had chance to upload them.

 

Hot idle at 60psi seems a bit high ?

might explain it running hot - everything just a bit tight ?

I would also thought that you'd want a thinner oil for running in than normal running for this reason as everything will be a bit tight.

 

****!!!
Who rebuilt it? German Subaru dealer? What do they say??
Hope it is all fixed soon

 

I think 10W40 results in the slightly high oil pressure. Better high pressure than too low!

High temps were the same before it blew, so I expected them to go back to sensible temperatures after the rebuild .

Re-built by a knowledgeable Subaru dealer, to whom it will shortly be returned for proper fixing...

Richard

 

Was this car standard other than the PPP ?

 

You could have several problems. With the boost problem, If I recall correctly the standard wastegate is set to open at about 7psi. So it maybe worth checking to make sure your purge solonoid is working, and the asscociated pipework is in the correct place (restrictor pipe etc).

As for the hot running, I'm rather unsure on that one, do you know the coolant temp too?

 

Moray, it did have a different air filter on, which will be replaced as soon as my STi filters arrive in the next few days. Otherwise standard PPP. New MAF sensor, thermostat and oil sump ring installed during engine rebuild.

I suspect the turbo hoses at the moment for the boost problem, so I'll try to have a look at that tonight. Not so easy to tell though, I suspect...

No idea about coolant temps, other than that the water gauge in the cockpit reads spot on the middle as always. But then again, it did when the engine let go last December too . I'd like to connect it up to a Select Monitor to check everything, but the only Subaru dealers round here are complete muppets - one of them insisted it was a Japanese import until I proved it was a UK-spec (= EU-spec) car ! My best dealers (the ones I trust) are over 150 miles from here .

Richard

 

Hi Richard,

Not sure if I'll make the meet yet, need to fit gearbox and diff to my car and it may only be possible over this weekend. For sure, if I'm there then I can give it the once over with Deltadash. What failed on the original engine?

Has the oil temp always been this high? Where is the sensor located? Do you monitor oil pressure too? And was a new oil pump fitted after the failure? Lastly, what filter do you have in currently, panel or cone, and have you ever cleaned/re-oiled it?

You can confirm your knocklink by tapping the bolt holding the new sensor in with a German style house key Light tap should produce big red. I'll have det cans with me anyway, if I make it.

Richard

 

Hi Richard

Ok, answers in order...

MAF failed on original engine, causing detting and overheating, and eventually piston #3 let go. New short engine, 150 miles ago.

Oil temp gauge fitted Aug last year, oil temps always this high since then - prob MAF was already on the way out. Sensor is (I think) located next to #3 cylinder in the bung there, to be confirmed. Oil pressure seems fine, around 100psi when cold, drops to 50psi on idle when warm. No new oil pump (I think - need to check the German again!). Unifilter, re-oiled at service at the same time as gauges fitted (major service), probably caused MAF sensor to fail. Now have a new-style MAF sensor and STi filter will be in in the next few days when it arrives from ScoobyMania.

I'll check the KL on Saturday with Neal (cheeseboy) and also the intercooler hosing then - I suspect it's the "fat boy" hose from the intercooler to the throttle intake that's cracked.

Assuming that goes ok, I might take a leisurely trip over to the Smagon meet, otherwise it will stay at my house until the dealer comes to look at it, from Friedrichshafen!!

Cheers
Richard

 

agree with ALi-B , it sounds like the restrictor might be on the wrong side of the "T" to solenoid.

dowser

are you fitting the 6speed JDM?

if you are what are you doing about the rear diff , as I am under the impression that the sti diff could not go on a classic due to flange and hub differences.

 

Pipework should still be in the right place, and it was making up to around 15psi initially after the rebuild, so I don't think the restrictor's misplaced. I'll bear it in mind though...

Cheers
Richard

 

did not realise it had got 15psi after build

 

T-uk - what differences? Oh-oh

Fitting the diff into an r160 housing required effort (slight mod to housing), but the splines for accepting driveshafts looked the same.

I've loads of photo's, will try and post something up in Projects tomorrow....

Richard - if you're oil temp has always been high since fitting the gauge, I'd suspect the sensor. Equally, re-oiling your filter probably killed your engine indirectly by contaminating the MAF.

Your current boost problems *could* be the ECU dropped into safe mode because the filter is so oily that it's already re-contaminated the new MAF....be careful Was the unifilter a panel or cone, what's the STi one (never heard of one!)?

Richard

 

T-uk: no problem I omitted to mention it in this post, sorry!

Richard: I'm wondering about the sensor too. It's one supplied with the Autometer gauge, and the original housing doesn't fit the thread on the bung - therefore the mechanic constructed a new housing based on a new bung, and fitting the sensor to it. Perhaps this could be the problem somehow?

As you say, an oily filter almost certainly caused premature death of the MAF - hopefully it hasn't killed the new one, as it's a different part number and is (I believe) not supposed to suffer this failure. The STi filter is one imported from Subaru Japan by ScoobyMania (amongst others) and is an original fit part for STis. It's a high-grade dry panel filter and doesn't have the oil contamination problem. (The aftermarket one was also a panel filter, a drop-in replacement.)

Richard

 

The new MAF's don't suffer the same vibration related failures as the originals, but they still act the same way when coated with oil....they under-read and cause your car to det itself to death

Please be careful - if in any doubt swap your sensor with a friends....but only *after* you've gotten rid of that oily rubbish death-trap currently connected to your inlet...otherwise you'll run the risk of contaminating his too.....

Richard

 

Should note that STi changed their filter a while back <nudge nudge, wink wink>

I've lost one of the new type ones too (knocklink went spazzo one day, then I realised that the idle was ever so unstable ), so they are not imprevious to being killed when they don't like something about life

Hope you get things sorted.

 

Right, the air filter's coming out tonight then, and the old one's going back in! Have to find it first .

KL shows all ok on the det front though so hopefully 150 miles hasn't been enough to make it die yet...

Richard

 

Check your MAF for contamination at the same time - it's easy to remove (use a flat balde to break the security pin out if you don't have the correct torx driver). I'd suggest electrical cleaner would clean oil off, but don't know for sure. Will probably be better to just get a new one again.

Richard

 

Out of interest, where is it best to locate the oil temp sensor? There seem to be two main places - either in the bung near to the end of piston 3, or in the sump bung where you drain the oil. I think my sensor is at the end of #3 and my friend's is in the sump bung. Would there be likely to be much difference in temperatures?

Original Subaru filter now back in and it seems to be behaving regarding boost, though I haven't bin on a long run in it again yet. Engine feels like it is starting to loosen up gradually, having now done 200 miles. Still a baby really I guess .

Richard

 

All ill put in is dont run the 5w30 rated oil, its too thin (it says in the owners manual that this is for climates with 0 and below temps).

Tony

 

Yeah, but I live in Munich, where the temperature varies from -20 in winter to +40 in summer... so I would have thought 5W30 would be right? It's what Subaru use over here...

Thanks
Richard

 

You would be better with the 10w40 as that covers the full range of temps you state, the 5w30 covers 0 and below only (so the engine has less strain/warms up quicker), its too thin for higher summer temps and it will make your car sound very tappy

Tony

 

Update - boost problem FIXED!

And it was.... a bent boost gauge tube . I finally worked this out when I watched the way it behaved - very slow response time both up and down. Ten seconds under the bonnet solved it .

Now just need to get those engine oil temps down...

Richard

 

And in another exciting development... I stuck a thermometer wire down the dipstick tube, right into the oil, and the temperature showed 90.5C. The gauge inside was showing 230F (110C)! Also the fans in the engine bay come on and off only when I'd expect - e.g. when left idling for 10 mins in my garage.

So I'm starting to suspect that the temperature sensor is broken or ill-fitted... Better that than genuinely high temperatures .

Richard

 

i bet thats took a load of your mind

 

Rich,

Do bear in mind though that the Oil Temp in the No.3 Gallery and in the sump are likely to be different. I'm sure I recall a long time ago, Bob stating that there could be up to 10-20degC difference between these two locations but this also depends on when/how you are measuring it. For example, if you are cruising, the oil in the sump will be cooled by the airflow. Also, if you are ragging it (not that you would ), the temps in No.3 are going to rise much faster than in the sump due to the location (I'm guessing!). I guess if you are stationary when comparing results, they should be closer.

Using decent 10W40 on my MY00, with the Defi sender in No.3 gallery, average temp was 80DegC though on track, up to 110 was normal.

Hope that helps,

Matt

 

No ragging involved (running in the new engine). So I think I'll try moving the sender to the sump bung and watch the temperatures from there instead - I guess they should be in the range of around 90C-100C in normal driving then?

Thanks
Richard

 

just read the whole post
nice to hear a happy ending well done m8tee