TD5 turbo issues

Fun and games with Turbo issues on my de- egr’d 2004 TD5 Discovery.

I had a stage 1 remap from Gary at TD5 Alive last year at Billing and at the same time he made sure the wastegate arm on the turbo was free to move and he tweaked the setting on the arm itself. Subsequently I’ve removed the viscous fan and replaced with a Kenlowe, fitted a bigger intercooler and a de-cat stainless exhaust. All has been well up to now and I’ve been pondering a stage 2 remap having fitted a turbo boost box to avoid the potential overboost issue. Last couple of weeks the car has gone into limp mode in the ECU and not allowed me to accelerate past about 2800 rpm. This normally happens when the engine gets warm on a longish run.

I have checked fault codes on the Nanocom and been getting a 20-02 Turbo Overboost error which when cleared and the engine restarted will go away for a short while but soon returns.

Having trawled the usual forums I’ve got plans to check the MAF, Oil in the injector loom (although this had been changed by the previous owner) and cleaning the MAP sensor.

Anybody any other bright ideas what might solve this problem? I’m not keen to spend out on more toys (stage 2 re-map, Hybrid turbo, ceramic manifold etc.) whilst this continues…..

Cheers,

Steve

My Guess is this.........

www.discovery2.co.uk / Waste Gate Modulator - Over boosting

If you connect your nanocom and go for a spin, at any point your over 2500 rpm, if the reading goes to 0........then the modulator is duff.

Thanks for the 'heads up' UP, I'm planning to systematically work through all the possible options. Ill let you know how I get on,

Steve

My guess is.................

Your engine is overheating due to the larger intercooler and the removal of the viscous fan and the tuned motor.

The more power you create in the engine the greater will be the heat and therefore demands on the cooling system.

Before you do anything else I would be putting the fan back on - and this comes from an advocate of no fans !!!!!

Mmmmmm.... sort of see where your coming from but the temp gauge stays firmly in the normal place and nothing feels paticularly hot. According to the Nanocom the coolant temperature is within expected ranges,

Steve

synapse said:

Mmmmmm.... sort of see where your coming from but the temp gauge stays firmly in the normal place and nothing feels paticularly hot. According to the Nanocom the coolant temperature is within expected ranges,

Steve

Click to expand...

Hi Steve, if you know for sure it's not overheating then ignore my comment and go with UP's boost controller doo-hickey. They are only about £20 to buy.

If you have Nanocom or similar you should be able to identify if the controller is working properly or not.

Had a similar problem recently...

It turned out being a cut in the hose going from the turbo-to-intercooler hose to the turbo wastegate modulator. Since the ECU did not read turbo boost pressure correctly it was unable to control the wastegate as it should.

Eventually hooked up Nanocom in READ FUELLING mode and read MAP (manifold absolute pressure) in real time while driving, on reaching 230 kPa (1.35 bar) could feel the ECU going into limp mode, also wastegate modulator % reading was zero. Stopped the engine, reset fault and off I went, actually drove it limited by MAP for a while until I got home and figured the problem out. The cut in the hose was hard to see as it was hidden behind the vacuum pump, also the hose was abnormally brittle as compared to the other two (heat checking?)

You're looking at a failing wastegate control mechanism by means of:

- Malfunctioning wastegate modulator (fried, unplugged, bad signal, bad connection, etc.)
- Malfunctioning wastegate actuator (stuck piston, seized inner spring, loose shaft, etc.)
- Disengaged or clogged hose (there's 3 of them)


_____________

Matt



PS: on a previous Discovery suffered 'kangaroo' effect from a clogged wastegate actuator to modulator hose.

Thanks for the above. I've put some time aside on Wednesday to look at this problem and I'll let you all know how I get on...


Steve