Delica Canada | Mitsubishi Van Club

I have been following posted procedure on freeing/lubing my wastegate actuator rod (my van had an intermittent hiss from the turbo area on startup and under hard acceleration):

http://www.mdocuk.co.uk/forums/viewtopic.php?t=4485

I am able to remove the big air intake hose to make room and the actuator itself to pull it forwards and backwards, but the casual comments to "lube the rod" have me stumped. (disclaimer - I do not have access to a hoist, and I could not find the actual pictures referenced in the above thread)

There seem to be three places which could benefit from lubrication:

1 - where the actuator rod disappears into the vacuum actuator itself,
2 - where the rod connects to the wastegate butterfly/valve, and
3 - the wastegate butterfly/valve itself.

The actuator rod is on the back of the actuator (when looking from the front), so #1 is virtually impossible to see, let alone lubricate. I had minor luck holding a can of WD40 backwards with the dispensing nozzle snaked around the various oil lines in the area.

Since the exhaust section of the turbo is towards the rear of the van, the rod disappears back away from the poor mechanic (me) such that #2 is even harder to see/reach/lube, surpassed in difficulty only by #3 which is completely hidden from view.

Lastly, the tightness of the other components around the rod make it impossibile for me to reach in and get a strong enough grip around the rod to shove it back and forth against the pressure from the spring inside the vacuum actuator (to see if the wastegate butterfly is working smoothly).

So long story, but has anyone else on this forum done this little piece of PM themselves? Is it way easier from the underside (I crawled under but couldn't reach anything). Am I missing something obvious?

Thanks,

Tony.

So long story, but has anyone else on this forum done this little piece of PM themselves?

I tried, but I basically gave up shortly after popping the hood... I think I'll try again when it is warmer out...

Been reading more UK posts; it appears that once you remove the two 12mm bolts, the actuator can be slid off to the side, allowing better manipulation of the rod/wastegate. Have to try again and see.

Also, there is supposedly a pressure relief valve (emergency relief in case of sudden pressure burst or failed wastegate) on the rear of the driver's side of the intake manifold which can coke/rust up and/or otherwise lose its springiness, causing it to pop early. Better check that too.

Always something to fiddle with!

On a side note, Happy New Year to all!!!!

"May the best of your past be the worst of your future!"

I'm keen to know the outcome of this as my first guess for hissing would be a vacuum system problem (the pipes are all over the place and a few are right bellow one of the intercooler pipes). Is the transfer case working ok - high/low range - 2wd 4wd?

Cheers,

peterh wrote:I'm keen to know the outcome of this as my first guess for hissing would be a vacuum system problem (the pipes are all over the place and a few are right bellow one of the intercooler pipes). Is the transfer case working ok - high/low range - 2wd 4wd?

Cheers,

I can't speak for the original poster, but I can assure you that in my case the problem is not the vacuum system, but the turbo. I have no vacuum related issues, however when accelerating hard I hit a point fairly quickly where I feel my boost vanish as a loud hissing sound appears, backing off the throttle slightly silences the hiss immediately.

My importer noticed the issue and thought it might work itself out, and on my L300 which started with the same problem it did in fact work itself out over time, but it took a couple of years...

I too am 90% convinced that it is a valve issue, most likely the PRV on the rear of the intake manifold.

Hiss starts at around 2K rpm, back off on throttle and instantly goes away.

Very occasionally, right when I start 'er up, there is a hiss from under the hood which fades away after about 2 seconds (too fast for me to dive under and see where it is coming from!

To me, that smells of a seating problem with the PRV, and given where it is pointing (right at the driver thru the firewall) the noise type and volume adds up. It is a high pressure hiss of excaping air, not a louder lower whoosh of exhaust gas going thru the wastegate.

I have reached back and pulled on the PRV and it begins to unseal with relatively little effort, so I think the spring and/or some other sealing component inside it is feeling its age.

I need to beg borrow steal or (gulp) buy a boost gauge and see what pressure the manifold is getting up to under normal running conditions. One of the problems for me is that the problem only really seems to manifest itself when actually running under load. If I rev it stationary, it doesn't seem to rear its head, so's I can feel the PRV while its actually happening (typical )

I hope its not the PRV, since it looks like a bugger to get off (big frigging hex mount, very little room for large wrench).

I'm tempted to wrap a rubber band around the PRV and see if the hiss goes away, but I took the turbo wastegate actuator off to one side yesterday which allowed me to lube the hell out of the pivot joints as best I could, and it looks like my wastegate is stuck shut. If this is the case, the PRV might be the only thing between me and a big ol' repair bill from an overblown engine

PS: Perversely, it looks like running at a reduced boost pressure has actually improved m MPG noticeably. It would stand to reason that I would be ultimately punished for fixing something on the vehicle

Green1 wrote: I can't speak for the original poster, but I can assure you that in my case the problem is not the vacuum system, but the turbo. I have no vacuum related issues, however when accelerating hard I hit a point fairly quickly where I feel my boost vanish as a loud hissing sound appears, backing off the throttle slightly silences the hiss immediately.

My importer noticed the issue and thought it might work itself out, and on my L300 which started with the same problem it did in fact work itself out over time, but it took a couple of years...

Ok, I'm convinced too you are a more patient man than I to wait a couple of years for this sort of problem to work itself out.

Asume you now drive an L400, have you put a boost guage on to check? Your hissing may be the relief valve????

This may help too.....
http://delicaclub.com/viewtopic.php?t=7 ... =wastegate

OK - quick, easy and free test for your Pressure Relief Valve (PRV) which seems to have helped my little hissing problem and power/boost loss.

Firstly, put on some rubber gloves and an old shirt if you have them!

As mentioned earlier, the PRV is a small round spring-loaded device on the rear of the intake manifold, pointing at the driver through the fire wall. In theory, it is set to open up at around 12-14 psi to prevent engine overpressure.

When the engine is at idle or stopped, it is difficult to grip the skinny outer plunger ring of the valve and pull hard enough to open it.

But when you spin the engine up to around 2500 rpm or so (either with a friend on the throttle, or by reaching around with your right hand and tugging the throttle cable) you raise the manifold pressure to a few PSI short of the valve popping open on its own. Now a relatively gentle tug will get it to spring wide open.

When I first did this, the opening motion coupled with the outrush of 12 psi air blew a satisfying amount of evil black oily crud the consistency of lard out of the PRV and onto my hands, jacket, face, etc. in a small cloud.

Popping the valve open and letting it shut again, rotating the plunger, and repeating about a dozen times blew out less and less junk, until now it seems (relatively) clean.

More interestingly, it became slightly more difficult to open as it cleaned itself out.

I believe that 15 years worth of accumulation from crankcase breather fumes, etc. had built up around the valve innards, impairing its ability to seal properly.

It might be wishful thinking, but the van now seems to rev more freely and pull stronger at higher revs. My ears are still buzzing from hugging a revving engine for so long, so I can't tell if the hiss is gone, but it seems to be an improvement.

Time will tell...

This is why it free'd itself on it's own eventually too, good highway trips actually help clean this sort of junk out, though your method is undoubtably faster, more satisfying... and a bit messier

As for what I have and have not done... with the weather hovering around -20c ever since I bought the vehicle (with very brief periods around 0c) I really haven't done very much, when we get some decent weather again I'll tackle some more of the issues on the wait list... and this is definitely one of them!

Stuck on a boost gauge - $25 at Princess Auto - and I'm running about 11 psi at full throttle, so she seems to have no noticeable leaks in the intake manifold now. I've noticed my mileage has gone down again, so I'm betting I was running at a lower boost level for a while.

Next stop - EGT gauge!

tonydca wrote:I believe that 15 years worth of accumulation from crankcase breather fumes, etc. had built up around the valve innards, impairing its ability to seal properly.

Correct-o-mundo

Could someone please post some pics of the actuator rod and the pressure release valve?

I think I need to give mine a cleaning as well.

Thanks.

with better weather today I tackled this project, however I ran in to a few problems...

tonydca wrote:When the engine is at idle or stopped, it is difficult to grip the skinny outer plunger ring of the valve and pull hard enough to open it.

at idle, or with the engine off, the valve on my L400 can be opened by hand with relatively little effort.

But when you spin the engine up to around 2500 rpm or so (either with a friend on the throttle, or by reaching around with your right hand and tugging the throttle cable) you raise the manifold pressure to a few PSI short of the valve popping open on its own. Now a relatively gentle tug will get it to spring wide open.

When I first did this, the opening motion coupled with the outrush of 12 psi air blew a satisfying amount of evil black oily crud the consistency of lard out of the PRV and onto my hands, jacket, face, etc. in a small cloud.

Popping the valve open and letting it shut again, rotating the plunger, and repeating about a dozen times blew out less and less junk, until now it seems (relatively) clean.

well, I got the engine running, and revved it up to... well, hard to tell, I can't have my head under the hood and see the tachometer at the same time... I pulled the valve open and shut a bunch of times, rotated it, etc... no large amount of oily gunk ever came out, and it never became any more difficult to open...

I'm starting to think I need a new valve...

Green1 wrote:
at idle, or with the engine off, the valve on my L400 can be opened by hand with relatively little effort.
...
I'm starting to think I need a new valve...

Like they say in West Virgina - It's All Relative...

But seriously, folks. Perhaps you have more of a kung-fu grip than me, but the issue I found was trying to grab the skinny lip with any kind of grease on my fingers.

If you haven't already done so, before you invest the $$$ and time in getting that #$%^#$% valve out, you might want to consider installing a boost gauge.

Mine was $25 at Princess Auto and less than 2 hours labour. Works a treat, all parts included.

If you're showing ~11psi at full throttle with a hiss, your problem may lie elsewhere, KemoSabe.

FWIW, I ended up having *two* hisses under throttle - a gunked up PRV and a coked-up EGR valve. Now with the former cleaned and the latter blanked off, she holds a rock-steady 11 psi under throttle, and mileage is noticeably better (combined city/hwy of ~12L/100km vs. 15+ before).

I find the boost gauge a very useful mileage improvement tool especially when driving on the highway. Running at just under full boost (say ~9.5 psi) by backing off just a smidge on the throttle make a big mileage improvement too.

I did discover that the bolts on my EGR were loose, though the valve itself appears operational (or stuck closed, but certainly not open) but it is possible I was loosing pressure around it's fitting... the bolt holes seem possibly stripped, and there's also no gasket of any form in there, so I'm not sure if I managed to get it all properly tightened down now, but it is possibly an issue as well.

As for the PRV, it seemed to open equally easily at idle/engine off as it did at high RPM...