Evening all
I've been roped into working on a ej20T engined rally car that belongs to a friend... but it's a bit outside my comfort zone as although I know my spanners I'm more used to land rovers and classic cars (I've built a v8 engined mgb gt rally car and am currently working on a sprint/hillclimb midget)... So I figure before I get stuck in any further I'll find some people who know a bit more than me.. hence I'm on here!
Righto.. onto the car.. it's a classic impreza (full fia spec rally equipment)..but the prolem is the lump so I'll stick to the specs for that.. EJ20T, it's got a tdo5 turbo, prodrive ecu & bailey dumpvalve (thats all I know of.. there maybe other bits/bobs my friends forgotton to mention and I didn't spot).
The problem started at a race last year when the car flew for the first quailifying but then developed a bad misfire and an alarming rattle on no.3 cylinder! I've looked and spotted that the coil pack was dead.. changed this and it now runs a bit better but the rattle/knock from the back of the engine is still there! So.. I want to identify what the noise is.. from my more classic roots I'm thinking compression test & stethoscope.. but Im sure there must be a more modern way?
We do have a spare (good) engine which we can put in.. so we might go down this route. but.. I don't want to put another engine in only to find the failure is something to do with the mods made (overboost/rev limit?).. hence why I'm keen to id the failure.
So.. ladies and gents.. your thoughts please!
Jim

 

rattle knock, could be big end dying, quite a common fault if the engine has been detting due to poor fuel etc.

 

I'm no expert either mate, but i would suggest as a starting point searching through the threads on here for the bailey dumpvalve!

That was where my problems came from, and suspect others will be along shortly

 

As said it could be the crank bearing on cylinder 3(This one is closest to the turbo), It might help to take the sump off and see if there is any play with the rod/crank, It does`nt always shop up this way but its worth a look,

Search youtube for a sound/vid file for `Subaru Knocking engine` see if you have a simaler noise/issue

 

The slightly albeit not really modern method, but best method to test for individual piston or valve related compression problems is a leak test. If that doesn't show up anything drastic then it could be a whole host of issues from bearings to hydraulic lifters. Probably worth using the stethoscope to pinpoint if it's head or crank/piston related.

Graham

 

Drop the oil through a clean cloth and check for debris, it could be many things but crank issues are very common and often mistaken for followers/little end etc. This will take 10 mins and the first thing I would do, you could spend a few hours trying to look in the cylinders, comp test etc etc. if the oil is clean happy days and try the other stuff.

 

if it doesnt run a baffled sump then im going with the big end vote, as mentioned very common in normal road cars anyway.

 

Thanks for the advice!
Well.. yesterday was hard work. started at 9 and finished at 9! with only two stops for tea and bacon butties!
Did the old diagnosis stuff.. listened to the youtube video's of big end rattles and compared it to the rattle we have... then the proper tests..1,2 & 4 all had good comparable compression, 3 though was slightly down. Stethoscope showed the rattle to be coming from the back of the block around the no.3 area.. so diagnosis is that the big end on no.3 is shot As we have a spare engine it was then a matter of getting the engine lift out and unplugging/wiring etc the block... wish I'd remebered about the fork through clutch bearing as it would have saved an hour of head scratching as to why the lump would not come free! Also It was only after pulling the engine out and putting on the bench next to the second lump we spotted that the two lumps were slightly different.. The car is a 94.. and the spare engine is a 94.. but the lumps thats come out appears to be a 97 unit (slightly different intake manifold assembly etc). So luckily we have a 94 intake assembly too so we are going to have to try and out together something from the two... eek.. I had carefully mapped the wires/tubes etc but now I'm facing a plumbers nightmare as nothing is going to quite go back in the same way. This is where we ran out of time and I needed a serious lay in the bath a a few beers!
So.. I have another list of questions that you guys/girls maybe able to help with

Clutch - the cars got a 4 paddle organic assmebly fitted.. upon removal it looks heavily worn to me with about 1mm of "meat" showing above the rivits on each side.. but then im used to landies etc where 5mm is the norm.. so is this worn or is it normal?

Turbo.. bigger = better? We have 3 different turbos available for the refit.. the tdo5, a tdo4 and a tdo5 that has had a coller fitted to the intake to restict the size (aparently it's somethign they do to certain rally cars??). All three spin freely with no nasty noises and no back/forth play in the fan.. but all three have some very marginal side to side play in the fan assembly? I've been told that this is fine so it gives us the choice of 3? I'm thinking that the un-reistricted tdo5 is the way to go.. but I'm no expert so your thoughts please...

Sensors - On the 97 engine there appears to be an extra lambda sensor prior to turbo on the exhuiast manifold? It's been wired into the loom too! But on the 94 lump there is no provision for this on the exhuast.. So.. can we transfer the header assembly over from the 97 engine to avoid having to messing with the wiring? Will it fit (baring in mind the intake assembly wont)?

And finally - is there anywhere on the net an idiots guide to the plumbing of a EJ20 turbo engine? The "normal" things like water hoses, heater hoses, brake vacum pipe and the oil/water feeds for the turbo are obvious.. it's just all the small vacum hoses for the intake/boost control/dump valve that are worrying me as they all seem to route slightly differently on the new lump so I can't just go with my markings!

Cheers in advance.. Jim

 

ive just rebuilt my engine at a cost £7000 i had std sump pad with the oil surging it caused no 4 big end failure youre best using a cosworth baffled sump bit pricey but they do the job