So when I was taking apart the engine that came out of my project RX, aka the marvel of redneck engineering (car had more things half assedly-rigged than I've ever seen) I found something interesting. You EA82T guys will be familiar with how the wastegate has a vacuum line running to the passenger side strut tower, and there's another vacuum line on the outlet of the turbo going to the plenum that runs to that area as well.

 

Here's those two lines as removed from the strut tower area:

 

And here's how the hookups for those lines were attached on the turbocharger:

Yes, they directly jumped the hookup from the wastegate to the hookup on the outlet to the plenum!

 

And here's the final deathblow that killed the engine (besides several other potential causes of death that I found):

 

 

 

 

 

 

So would this have totally inactivated the wastegate? I'm sure the car didn't last long if that was the case. Also seems that the ECM was never getting any signal that the engine was boosting, as the sensor for that reads from these lines, doesn't it?

 

Many things convinced me that the car was last put together by an idiot, but this one really takes the cake.

 

Could we be looking at the cause of the thrown rod?

mine looks like that, plumbed from the plenum to the wastegate, the hoses going to my strut tower is for the turbo light and the second hose is to cut fuel to prevent damage(IIRC)

i have a spare turbo off of my old parts car. the wastegate actuator hose was plumbed right off the compressor side of the turbo, like in your pic. i dont know what year it was, but it was at least 1987 because it had a hotwire maf.

Hm, I didn't think they were supposed to be like that. My other RX was set up differently, as well as the parts car I was picking parts off of.

 

 

Either way, gotta love that looped vacuum line. Totally useless!

hmm.. From what I've read, that thing on the strut tower those lines go to is some sort of boost controller that is used at high altitude (Maybe that is why my turbowagon likes to bounce between 10 and 15 psi at full throttle..) but that is all the Alldata thing we had at school said about it. No clue when it's used or anything...

Hmm, didn't know that. I just figured it wasn't supposed to be lined up like it is in the pics, as 2 of 3 that we worked on lately were set up differently and appeared to be original. Wonder if cars sold in different regions of the country were hooked up differently?

 

Now I'm wondering if the other way I hooked it up was wrong.

 

Guess you learn something new every day.

the old engine in my gl turbo had the exact same problem....put a hole in the exact same spot too

my wagon had the controler on the strut tower. (87 T-wagon). when i got the JDM engine for it the hose was looped. so i put that turbo on it ,looped. and i have been running it for about 20K now with no problem. boost is right at 6.5 - 7 psi.

That is NOT how any factory EA82-T car came, it has been done by a 3rd party along the way.

 

 

There is no harm in doing that as the wastegate is set at 7psi, so running a line directly from the wastegate to the outlet will still only let the turbo spool up to 7psi under all conditions. The reason people are doing this is because the stock boost controllers go bad over time and this is a cheap fix.

 

The bad thing is, at higher altitudes the boost wont be raised to compensate so you will LOOSE HP at high elevations, this doesnt hurt the motor at all just performance. Those lines were for Boost control under these conditions.

thats how mine is set up, it runs great, right up t0 8psi on mine though. bu it did end up with a boost controller put in that spot though.

Too much boost wont cause a broken rod anyway - the compressive stress on the rod caused by the piston is basically negligible compared to the bending stress caused by the rod's own weight.

 

More likely the rod broke because of over-reving, bad big-end bearings or bad oil supply.

I agree with Ross on this one.