therotaryrocket

Okay, so I've been working on my S4 TII and I have a wordy post with a few questions for ya. I put a JDM S5 TII engine in it and ran it for a while, fixed some things here and there. Well after 500 miles I decided that the turbo was bad after leaving clouds of blue smoke everywhere. I noticed a scraping noise from time to time and didn't quite figure it out, until I started suspecting the turbo.

A few preliminary things I should mention... I used 5W30 in the motor and I'm not sure if that could be contributing to the turbo scraping, but it has always shown good oil pressure. I had my ignition timing set way wrong at one point and caused the entire turbocharger and downpipe (as far as I could see from the engine bay) to glow red hot until bursting into flames (fire extinguishers are great!). This was with the old S5 turbo, and after I reset the timing properly it had the same symptoms as before, the scraping noise, but no it didn't catch fire or glow as intensely anymore.

I have also noticed that after resetting the timing the turbo still glows red, not nearly as bad as before though. Also, I'm pretty sure i'm getting around 150 miles to the tank which is really bad, but I don't have the oxygen sensor connected. I haven't had the chance to recheck my fuel mileage now that I fixed all of my vacuum leaks though, it may be normal now?

Also I don't have any emissions or cold start assist. In fact I plugged the rubber hose that normally goes from top of block to thermowax, would this stop the flow of coolant to the turbo?

I looked at the compressor fan and noticed some missing/bent blades on the fan. Also the turbo had a lot of in and out play as well as some side to side. Usually I would hear the scraping noise while starting the engine, and some times if it was idling but I hit the gas to rev it up I could hear the scraping.

So I took the turbine housing from the S5 turbo and put it on the S4 compressor and center section. I put it on the car and started it up today. I only heard the scraping noise once while it was idling and it only lasted about 2-3 seconds, this was after it had already warmed up. I still need to switch to the Castrol 20W-50 (tomorrow). Well I drove it and boosted it a couple times down and back up the road and popped the hood to find the turbo glowing again (not too intense).

I did some searching and found some threads where people say it's normal to see the turbo glow after a hard run, but the thing is, I am not doing a hard run. I'm running stock or less than stock boost levels on a mostly stock car (3" down pipe/highflow cat), and I only boost 1st and 2nd gear not even to red line, maybe like 6 of those pulls before I popped the hood and noticed the glowing.

I'm going to install my AEM wideband in a couple days hopefully and see if I'm running lean. Some questions remain though.

Did I accidentally block coolant flow to the turbo by blocking off the hose that goes to the thermowax?

Could the turbo glow red after only a few pulls?

What is causing this scraping noise? The S4 turbo I installed has very little play in all directions.

Could the lack of heat shields cause problems with the turbo? i'm so forgetful

One unrelated question, what does the thermosensor looking thingy on the top of the S4 water filler neck go to and/or do? I noticed the connection is really bad and it seems somehow connected to the A/C electric fan?

Thanks everyone for your wonderful expertise. It's much appreciated as I'm trying to get ready to go autocross this biatch!

SpeedOfLife

iTrader: (16)

I would recommend you reconnect your O2 sensor. I think the coolant to the turbo runs from the block through the LIM, so you should be ok there. Wideband is a good idea. I'm sure the turbo could glow after a few pulls, the glowing will appear exaggerated in low lighting, but the wideband could help you determine some things. Find TDC and make sure your timing marks are dead nuts on, the pulleys and hubs varied through the years. I mismatched a set of hub/pulley despite both of them coming from same year same model motors and it gave me a lot of grief (SUPER retarded timing, bright orange turbo, full boost at light throttle, it was horrible). The scraping I'm not sure, but eliminate any loose pipes/hoses/cables et cetera as culprits by checking carefully around your engine bay (especially around belts, pulleys, fans...). Lack of heat shields will give you higher under hood temps and thus make your intake temps higher, especially with it being right under the intake manifold. I modified my stock heat shields for ease of removal/reinstallation and to stay out of the way of the S4 twin scroll, but the upper portions are vastly unchanged and I believe those are the most important parts (to keep the heat from rushing straight up to the LIM).

Search on the thermosensor, I know the answer is around, probably even in the FSM.

RotaryRocket88

iTrader: (7)

The coolant feed will be just fine with the thermowax bypassed/capped. And the thing on the filler neck is the 207* temperature switch for the electric fan.

coolmike711

iTrader: (7)

The scraping means the turbo is shot. I think your timing is still off, fuel is burning inside the turbo that's why it's glowing.
That happened to me after my rebuild. Couldn't understand why at idle the turbo was glowing. Rechecked the timing and problem solved.

arghx

iTrader: (3)

mismatched pulley/hub resulting in incorrect timing marks?

therotaryrocket

that sounds like a possibility, I'm using an S4 front cover with the S5 crank pulley? did I eff up? How would you check for actual TDC on a rotary? If the rotor face is against the spark plug hole on the front rotor? Hopefully that's the problem cause I'll throw the S4 crank pulley back on if need be. So would the glowing turbo represent retarded or advanced timing?

thanks for the help guys.

coolmike711

iTrader: (7)

I had to retard mine alot for the timing marks to line up. Once the timing was set no more glowing.

therotaryrocket

Well I definitely overlooked the small things this time, it turns out that scraping noise I was referring to was actually a loose alternator belt causing the water pump pulley to vibrate. And yes, I do feel like an idiot. Anyways, tightened the belt and I'm feeling a lot better about things now.

I still have the issue of a glowing turbo, and so far my plan is to...connect my wideband O2 sensor as well as recheck my timing. The only problem is my car is idling around 900 rpms, and I assume I would just compensate by allowing it to advance a very small amount past the mark?

I have this combo, S5 engine, S4 front cover, S5 front crank pulley, should the timing lights and marks on the front cover and crank pulley all line up properly with this setup? I don't remember reading about differences here, but I do remember reading that the S5 engine has the spark plug holes at a different position in the rotor housing compared to S4 and I'm not sure if that could be an issue?

I've also been searching a little trying to find where to connect my wideband O2 gauge. I'm trying to find the best place to splice into the headlight illumination wire. I read on aaroncake's wonderful website that I should connect to the headlight illumination terminal, but I don't know exactly where to find that and I couldn't find a picture. I also need to run a wire from the stock O2 to the ecu, because I cannot find the original connector on the factory harness?!

Thanks for all the help, my shizzle nizzles.

arghx

iTrader: (3)

Are the pulley and the hub (the one the crank bolt goes through) from the same engine? Are they matched as a set? If they aren't, your timing marks are probably wrong. This isn't a huge deal on an n/a engine but on a turbo motor it can lead to engine damage.

people make a big deal about the plug holes. it doesn't matter that much. you've got 93 octane in a motor that was designed for 87, it'll be ok. In terms of motor blowage potential, what's most important is when they fire. And on a stock computer the only thing you can do that will change that is installing the crank angle sensor incorrectly due to bad marks. And why is your idle so high?

What wideband gauge do you have? You only need to hook it to an illumination wire (red/green wire in the cluster, headlight switch, and radio area) if it has a backlight to it like your typical autometer mechanical boost gauge. If it's something like an AEM gauge or an innovate gauge, you can hook it to another source of switched power.

SpeedOfLife

iTrader: (16)

I wouldn't trust the timing marks at this point. Find TDC by using either fluid displacement method or checking the plug holes, both methods were recently detailed in another thread in this section. Hailers was in there talking about the fluid displacement. A search should turn it up.

Your wideband gauge will do you NO good without an accompanying wideband sensor... you didn't seem to specify that you have one so I'm making a point of this. The stock O2 sensor is not particularly useful for anything other than telling the ECU if you're WAY rich of 14.7, a tad rich, a tad lean, or WAY lean of 14.7. It's not a precision instrument when compared with a wideband sensor.

Also, what are you trying to do with the headlight illumination wiring? Night time light for the gauge?? In any case, the FSM may help you find what you need there.

The factory O2 sensor connector in the engine bay (this is for S4 TII's, but I wouldn't be surprised if it's the same for S5 TII's) is right in front of the BAC, right behind the solid coolant elbow coming off the water pump. It's a single wire with a goofy square plug (squarish looking at it from the end). Mine is a yellow male connector and the O2 sensor end on mine is green female (bear in mind this is male/female in the sense of one goes inside the other, these aren't like other standard connectors I've seen).

RotaryEvolution

iTrader: (30)

did you bother to install the 2 step fuel pump relay? can't count how many people do the swap thinking its all plug n play ****... hopefully if your car was originally a T2 it should be there, somewhere.

PvillKnight7

iTrader: (16)

Your turbo might be glowing from excess back-pressure caused from a clogged catalytic converter.

SpeedOfLife

iTrader: (16)

3" DP and high flow cat. Shouldn't be a problem there.

I wanted to note for going from 5W-30 to 20W-50. Unless it's real cold where you are you don't want to use 5W-30. It's been hovering around 0 in Iowa for weeks and I have 10W-30 in mine.

therotaryrocket

thanks for the replies guys,

okay the only reason I used 5W30 is because that's what we have at the dealership I work at, so it's sorta kinda free and very convinient.

Yes my car was originally a turbo II, but Karack are you referring to the fuel pump relay thingy that drops the voltage at low load and steps it up when neccessary? I plan on rewiring my fuel pump and keeping that relay as described on 1300cc.com.

SpeedofLife, I have the AEM wideband UEGO kit which has the gauge/controller unit, harness, and wideband sensor. Also, I will definitely take your advice on confirming TDC and search on the how to.

btw, my stock O2 sensor connector must have disintegrated into thin air because I don't see any more wires on my harness. i guess I'm going to just run a new wire from the stock o2 wire to the ecu, but don't a lot of people run their 7 with the O2 disconnected with no problems other than a slight reduction in mpg (1-3 mpg)?

I don't know how old the catalytic convertor is, doesn't look very new, and I did remove all emmissions and airpump, will that cause the convertor to clog? I'm kinda worried about this because I removed the airpump, does that mean the convertor does no good or just less good?

thanks for the help, pointing me in the right direction

SpeedOfLife

iTrader: (16)

I'm sure there are people who do, but for fuel economy alone I'd wire in a new one. Going without one seems pointless to me, too, because I'd think light throttle power/response would suffer.

It could cause it to clog. I'm not sure on the details about how well the cats operate because that's one of the first things to go with all my cars. I hate cats.

PvillKnight7

iTrader: (16)

meow?

I had 3" on my 87 TII with a high flow cat. No emissions or air pump. As it became more and more clogged I had to press further and further down on the gas pedal to achieve the same speed. I noticed there was a problem when I topped out at 45mph at wide open throttle. When I pulled the cat, chunks of the honey comb like material inside the cat feel out. Normally you can see right through the cat if you hold it up to a light source but mine was almost completely closed.

/meow

RotaryRocket88

iTrader: (7)

Yeah, leaving the cat in place after removing the air pump is not the best way to go. As it is original cats are just waiting to plug up, so you sped up the process. Time for a presilencer.

therotaryrocket

sounds like a plan, I was kinda figuring a cat with no airpump would not fare well. I wish I could have some performance and cleaner exhaust, but that's a difficult task for these older rotaries and I don't have the money so yea i'll probably just chop it off and go 3" all the way back.

Got my Wideband O2 bung welded on and the sensor is mounted, now I just have to wire it up. Then I have so much suspension work to do in the next two days (subframe, differential, f/r lower control arms, and DTSS bushings, then front and rear shocks/struts and springs).