St205 Gt4 Turbo Problem

[Hot Hatch World]

Hi people,

I'm new here as you can see! I'm hoping you can help me out. I own a ST205 Celica GT4, and in the last few days the engine management light has come on, but there was no effect in performance what so ever, so I put it down to the fact that the car is in need of a service. (The next service is due at 90k, and the light came on at just over 90k.) Yesterday though the car seemed sluggish, and when I looked at the boost guage on the dash, it wasn't showing full boost. Before yesterday the needle going over the top of the guage, but now it only goes 3/4 of the way up it.

The car is completely standard except for a straight through exhaust. Any ideas what it could be? There was some oil on the back of the turbo, but I have wiped that off and there has been no more come back since, and I have checked the pipe coming of the top of the turbo, and there is a very small amount of oil in there, but notmuch at all.

Any ideas?

Thanks in advance

Matt

(Sorry I wasn't sure were best to post this)

[daktari]

Hi people,

I'm new here as you can see! I'm hoping you can help me out. I own a ST205 Celica GT4, and in the last few days the engine management light has come on, but there was no effect in performance what so ever, so I put it down to the fact that the car is in need of a service. (The next service is due at 90k, and the light came on at just over 90k.) Yesterday though the car seemed sluggish, and when I looked at the boost guage on the dash, it wasn't showing full boost. Before yesterday the needle going over the top of the guage, but now it only goes 3/4 of the way up it.

The car is completely standard except for a straight through exhaust. Any ideas what it could be? There was some oil on the back of the turbo, but I have wiped that off and there has been no more come back since, and I have checked the pipe coming of the top of the turbo, and there is a very small amount of oil in there, but notmuch at all.

Any ideas?

Thanks in advance

Matt

(Sorry I wasn't sure were best to post this)

←

Hi Matt. Welcome to TOC. You`re in the right place.

(Edited... Wrong car Ooops )

My first thought is that you may have a problem with the MAP sensor. This would tell the ECU to reduce boost pressure to avoid potential damage. Aren`t computers wonderful.

Have a look see and let us know.

[sotal]

Welcome to the club

Yes you have posted in the right place,

anyway just check out which fault it is throwing up. Do a search on here for how to get the diagnostics codes, the gen 6 sticky at the top has a post from me about what the codes mean. You simply bridge two pins in the diagnostics port (T1 and E1 ring a bell - but search to make sure!) with a paperclip or something similar. Then count the flashes in the car.

That will let you know what is wrong then you can go from there

[GT4 BOOSTER]

go to www.st205.net and look under " technical"

[Hot Hatch World]

WOW, you guys are superb for quick and useful replies! The code is number 54, which I can sort out, but it says to reset the ECU, but how do I do that?

Thanks again.

[Hot Hatch World]

Sorry guys me again! I thought finding the sensor to unplug would be easy, but I must not be as clever as I thought! I have added a photo, as I think I have found it, but want to check before I go unplugging random things I perhaps shouldn't!

I also can't seem to see any level markers on the coolant, but the car has never over heated even slightly, so I am crossing my fingers the coolant is OK!

Thanks

[sotal]

So you've got code 54:

Flash Type: 54

Fault Location: Turbocharger intercooler module - signal

Probable Cause: Wiring, coolant circuit, turbocharger intercooler coolant pump,turbocharger intercooler coolant level sensor, turbocharger intercooler

module/relay, ECM

To reset the ECU you can either pull the EFI Fuse out (think it was the EFI - search and you will find out for sure) Wait 30 seconds during which time you can press the brake to get rid of any stored charge, then put it back in or just disconnect the Battery completely wait a few minutes press brake etc then reconnect.

Once you have reset your ECU your car will run like a bag of sh!te for a few miles whilst it relearns everything. May even stall at junctions so be prepared and take it out when it's quiet!! :D

Sorry can't help with the sensor though

[GT4 BOOSTER]

the sensor is in the top of the chargecooler for error 54 next to the fill cap , just top it up reset the ecu and it should be ok . the coolant level is seen by topping up the charge cooler untill it runs out.

make sure you have the radio codes before dc the Battery .the efi fuse is the way to go .

[Hot Hatch World]

Thanks for all yur help guys. Went and bought some coolant, topped it up as described, then reset the ECU. No more engine management light, and back to full tarmac shredding performance!

Just got to work out why the fuel guage isn't working now!

[GT4 BOOSTER]

you will find as with all gt4's the petrol gauge always reads in the red lol. i'd look right at the eart strap on the sender unit on the petrol tank, although im not sure where it is on the gt4 . im tempted to think its under the back seats but not 100 % sure.

[Hot Hatch World]

LOL I'm starting to notice that myself. I will check that mate cheers.

[Hot Hatch World]

Sorry to keep being a pain chaps, but went out in the car after the problem had been sorted, and the damn light came on again. I noticed the coolant was low again, so I persumed I hadn't run the car for long enough to get the charge cooler working, so I have topped up the coolant again, and will check it again in the morning. There is no sign of a leak though. Could the problem not be the coolant?

[GTForbes]

it could just be an air lock in the coolant system, i've had one for ages, just hope i managed to finally get rid of it last weekend as i'll need to go out and buy some more coolant if i havent

keep topping it up mate, take a look on the GT4 owners club site and you'll see it's quite common www.gt4oc.net

[GT4 BOOSTER]

have someone rev the engine slightly , small blips now and again too whilst you fill it up - you will notice the level drops when the cooler pump kicks in , the sensor is very very tempremental

[Hot Hatch World]

I've had to put in a whole bottle of coolant, does that sound excesive? Every time the light goes out it will drive fine, then when the turbo is fully spinning the light will come back on and cut the boost back. I then need to re-fill the coolant, and reset the ECU again. Am I missing something? I can't see any visible leaks either.

[sotal]

I'm no expert but that doesn't sound good :(

It may be worth getting it checked by a specialist

[daktari]

Sounds like you are losing coolant somewhere. :(

[GT4 BOOSTER]

check the small fmic for steam , it may be holed , may also be the small radiator type cap on top of the charge cooler isnt holding pressure. , i suppose liquid rad weld would cure it if its a water leak, but please check first .

[Sirius]

Where are you putting the coolant? Code 54 is about the chargecooler so you should be filling the big black box ontop of the engine.

Code 54 usually means the level is low - although it can also mean that the pump has failed.

If you are loosing any more than a teaspoon in hundreds of miles then you have a leak. The fluid never gets very hot so I wouldn't expect to see steam anywhere.

When we say a whole bottle of coolant - how much is this? The total capacity of the system is only a couple litres at the most.