New owner - 95 Aqua blue VR6

[UKLonar 10]

Long time lurker of this forum, I've finally decided to jump on the bandwagon.

In the wait for my mk2 golf to be 3.2 swapped, I decided I'd fulfil a want of mine to own a Corrado! Enter this Corrado VR6, finished in Aqua Blue Pearl... 

The previous owner has spent a lot of time on this one it's had a full engine rebuild, respray, chassis/subframe refurb, uprated brakes, Jetex system & 6 branch and loads more.

It did however come with a few faults:

• Failed to start/turnover - I've replaced the ignition switch and this had fixed the problem.
• ABS light is on - Need to scan with VAGCOM.
• Radiator fans don't appear to work correctly.
• Speedometer + spoiler don't work intermittently - I've ordered a speed sensor for gearbox as this seems the likely culprit.

Now, hopefully you can help with the fan issue, as that's most pressing at the moment. It has an uprated, slimline set-up fitted on an alloy radiator. The car does get rather hot in traffic and as far as I can tell, the fans aren't kicking on as they should.. The only time I get a fan on, is when I switch the car off.. and only one of the two fans spin. Is this correct for over-run to only run one fan?

Now, what should I be checking? I've had a look through various forums and my issue seems slightly unique. I'm guessing I should first check the radiator switch on the bottom of rad on passenger side first?

It's also worth noting, the previous owner fitted a manual over-ride switch to turn these fans on, which I suppose I should have been more cautious about. 

Appreciate any support or links you might have, I'll post up a full thread soon as I've done a fair few bits already. TIA.

 

 

[Keyo 47]

Congratulations on the purchase - saw this car and went for a good price considering the work carried out and the recaro seats and alloys. 

Aftermarket Slimline fans - Shaun is the man for them on here- sounds to me likely to be set up wrong in the first place- if you search cooling guide on here its very informative - you can test by bridging all 3 speed settings. The fan control unit is a common failure point as well due to age .  

Basics first are to bridge the fan switch sensor (one in radiator) plug for settings 1 ignition off- setting 2 bridge same plug but different pins ignition on - settings 3 bridge the the black coolant sensor plug ignition on that is in a row next to the other 2 coolant sensors .  

Edited September 25, 2021 by Keyo

[UKLonar 10]

40 minutes ago, Keyo said:

Congratulations on the purchase - saw this car and went for a good price considering the work carried out and the recaro seats and alloys. 

Aftermarket Slimline fans - Shaun is the man for them on here- sounds to me likely to be set up wrong in the first place- if you search cooling guide on here its very informative - you can test by bridging all 3 speed settings. The fan control unit is a common failure point as well due to age .  

Basics first are to bridge the fan switch sensor (one in radiator) plug for settings 1 ignition off- setting 2 bridge same plug but different pins ignition on - settings 3 bridge the the black coolant sensor plug ignition on that is in a row next to the other 2 coolant sensors .  

Thanks mate, I'm happy with it overall. I think it was a good price.

I completely missed that guide, I'll run through some tests tomorrow when it's light again. I'm hoping it's something simple like a dodgy rad switch!

[Keyo 47]

6 minutes ago, UKLonar said:

Thanks mate, I'm happy with it overall. I think it was a good price.

I completely missed that guide, I'll run through some tests tomorrow when it's light again. I'm hoping it's something simple like a dodgy rad switch!

This is a late genuine fan switch from a good seller - check your pin lay out is that same as in a triangle as early has a horizontal 3 pin lay out. On diagram there is no sealing washer. 

https://www.deutsche-parts.co.uk/1h0959481b-switch-new-genuine-part.html

Edited September 25, 2021 by Keyo

[Cressa 43]

That is one great looking car and with a lot of nice goodies, not much it doesnt have. 

Great cars are worth paying for. Just a few niggles to sort out, but there is always something that is needed with all our cars

Well done in getting her 👍

[1xshaunx1 27]

It does look a clean looked after car. 
As Keyo says bridge the rad switch plug to bring the fans on if they don’t or one doesn’t there an issue with a relay unless he’s wired direct off of the existing fan plug. Do the above test and take some photos of the wiring, there’s a few ways he could have wired it up. When you press the  override switch what happens then, do they both come on? You should be able to get both fans on without the ignition on as well simulating after run by bridging the rad sender plug. 
 

[UKLonar 10]

Thanks all! It'll be sweet as once I've sorted all these little bits.

Went out this morning to test the radiator switch and got the following results:

In both test cases, the override switch switches the drivers side fan on, I suspect it may be wired to stage 1?

Igntion off

Bridge rad switch top left and bottom pin - one fan, drivers side (Stage 1)

Ignition on

Bridge rad switch top left and bottom - one fan, drivers side 

Bridge rad switch top two pins - one fan, passenger side (Stage 2?)

I need to test the black sensor for stage 3, maybe that'll trigger both fans..

Either way, it looks like the rad switch could be knackered. What do we think?

Will chuck some pics up of fan wiring when they've uploaded to imgur.

[UKLonar 10]

Imgur pics here - https://imgur.com/a/xXGL6TA

[1xshaunx1 27]

1 hour ago, UKLonar said:

Thanks all! It'll be sweet as once I've sorted all these little bits.

Went out this morning to test the radiator switch and got the following results:

In both test cases, the override switch switches the drivers side fan on, I suspect it may be wired to stage 1?

Igntion off

Bridge rad switch top left and bottom pin - one fan, drivers side (Stage 1)

Ignition on

Bridge rad switch top left and bottom - one fan, drivers side 

Bridge rad switch top two pins - one fan, passenger side (Stage 2?)

I need to test the black sensor for stage 3, maybe that'll trigger both fans..

Either way, it looks like the rad switch could be knackered. What do we think?

Will chuck some pics up of fan wiring when they've uploaded to imgur.

If you’re getting fan action bridging the plug and nothing when driving, as seems to be your issue then the rad temp sender would seem to be at fault. It curious that both don’t come on together for stage 2. I’d look into rewriting it there’s a thread or 2 on it. 

 

[UKLonar 10]

Great, I've ordered a genuine one from the link @Keyo provided. I've found that non-genuine ones are a bit hit or miss from previous experience. Hopefully that does the job and makes them work during normal operation. 

I've since asked the PO about the operation of the fans and apparently, the single running was how he deliberately set them up. I think in the future, I'll look into rewiring and getting both working.. makes more sense in my mind. 

[1xshaunx1 27]

I’d agree that you’d be better with two fans in operation as when the stage 2 fan engages as that’s the idea, one fan isn’t enough as the temp has gone so the rad sender engages the second stage, going from one fan to the other won’t improve your cooling one bit. 
It’s a nice little project sorting the fans and wiring out. 
Something else to bear in mind is the auxiliary water pump, you need to see how he’s wired the fans. If he’s bypassed the main fan controller unit chances are this won’t be running if the fans come on when you turn the engine off. You can tell if the auxiliary pump is working by just turning the ignition on without engaging the starter motor, you should hear the pump run for 30 seconds or so, no buzzing and it is duff. 

[UKLonar 10]

37 minutes ago, 1xshaunx1 said:

I’d agree that you’d be better with two fans in operation as when the stage 2 fan engages as that’s the idea, one fan isn’t enough as the temp has gone so the rad sender engages the second stage, going from one fan to the other won’t improve your cooling one bit. 
It’s a nice little project sorting the fans and wiring out. 
Something else to bear in mind is the auxiliary water pump, you need to see how he’s wired the fans. If he’s bypassed the main fan controller unit chances are this won’t be running if the fans come on when you turn the engine off. You can tell if the auxiliary pump is working by just turning the ignition on without engaging the starter motor, you should hear the pump run for 30 seconds or so, no buzzing and it is duff. 

Aux pump buzzes along as intended with ignition on, seems to go on for as long as I've got the key in that position.. albeit I only left it for around a minute. I took a short video to showcase this:

Worth noting, it also works when my overrun fans are working, so suspect that this is ok.

[Cressa 43]

Aux. Pump is designed to run continuously whilst with the ignition on. 👍

[Keyo 47]

Looks a good car can see the front member has been taken care of to.  

Edited September 26, 2021 by Keyo

[UKLonar 10]

1 hour ago, Cressa said:

Aux. Pump is designed to run continuously whilst with the ignition on. 👍

Excellent, I thought as much. Glad that's working as intended then!

 

54 minutes ago, Keyo said:

Looks a good car can see the front member has been taken care of to.  

Yes mate, cross member and subframe were both refinished, here's a pic.

[Cressa 43]

Oooo nice pic. We love freshly painted items more than xmas 😂

[UKLonar 10]

Managed to fit a new speed sensor on top of the gearbox, a little bit fiddly but an easy job really. Now have a consistently working speedo + Spoiler, happy days. I've got the radiator switch to fit soon, along with a few other bits. I also need to bleed to clutch because the pedal very occasionally likes to stay down a bit which is a little bit annoying.

I've got a random issue though, which is quite hard to describe and thus search for a solution on:

When I'm driving the car before it has warmed up, I sometimes get this very odd sharp braking sensation, it's almost like really hard engine braking or what you'd get if you quickly had a stab at the brake pedal. This usually happens just as I come onto the accelerator after shifting gear, in smooth operation.. not gunning it or anything. My mates reckon this is a misfire, does that sound right? I'm not getting any weird noises when it happens.

I would post in the engine bit, but I don't seem to have access yet 😉

Edited October 3, 2021 by UKLonar

[Dox 22]

I had a similar issue with my clutch, after several weeks the clutch slave Cylinder failed over night leaving no puddle of fluid underneath the car. Easy fix on these cars.

Engine braking sounds like a fuel supply issue? On my car the pump mounts inside the swirl pot inside the tank had rotted causing starvation on bends / roundabouts on low fuel levels - this usually affects early cars as late have a different pump set up.

 

It could also be fuel relay, immobiliser issue.

Watch the dash when it happens to see if the tacho falls to zero or still reads when the issue happens 

 

Are you a paid member?

Edited October 4, 2021 by Dox

[fla 9]

41 minutes ago, Dox said:

It could also be fuel relay, immobiliser issue.

Watch the dash when it happens to see if the tacho falls to zero or still reads when the issue happens 

My thoughts here too. Also could be the ecu relay 109. Same as Dox says, check if the tacho falls to zero when it happens

[Dox 22]

Battery connections and earth connection to engine / gearbox - clean, tight, intact?

[UKLonar 10]

Going to try a bleed of the system first to see if that remedies the clutch issue, I couldn't see any obvious leaks.

I'll check to see if RPM drops to 0 when the engine issue happens and report back. 

Will also double check earths in bay.

[Keyo 47]

Guarantee it’s the slave 

[fendervg 29]

Definitely slave - you might not see any leakage if it's not fully blown as the fluid will be inside the boot - sometimes a quick bleed of the slave, followed by the master (can be done with just gravity) will sort it for a while as a temporary repair, but the slave cylinder is not too dear and and a handy enough job compared to most others on the Corrado.

[UKLonar 10]

If the bleed doesn't make it go away, I'll grab a new slave cylinder. Looks like euros does the VW one? Anyone recommened where to get one?

On the engine braking front, I noticed that the breather valve on the inlet elbow was missing its bung. The previous owner had put a yellow cap in here but I've no idea where this has ended up. That unmetered air can't be doing a lot of good...

Oh and when the problem shows, RPM does not drop to 0.

Ordered some silicone caps and I'll chuck one on with a clamp, hopefully that sorts the problem.

Edited October 4, 2021 by UKLonar

[Tigerfish 10]

That’s normally connected to where that red filter is in the pic, so just crank case gasses getting pulled in.

 

 

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