Grill block = smoking
 

SO I done a rather basic grill block out of cardboard, painted it black and set off on my journey, engine temp was a little higher than usual but nothing to cause alarm, but there was a burning smell and smoke coming up from the bonnet. I pulled over and everything seemed ok, but I took the grill block off just to be safe.

A short while later I think I understood what the problem was. It was the lower grill and it was a 100% block. This is where my turbo intercooler is so I think that must have got crazy hot and maybe it was the pipes smouldering.

So where does that leave me? It has tiny upper grill anyway so I can't see much aero advantage in blocking it off.

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Question is, how do you folks with turbo intercooler grill block? Or is my intercooler shot as it is getting too hot too easy?

PS, that was overheating without even using the turbo as I drive so gently the turbo never kicks in at all.

I wouldn't mess with a bottom grill block on that vehicle. Since the upper grill is smaller the vehicle gets most of its cooling from the lower grill anyways and you deprived it of that. You still need to have everything function correctly for cooling and performance especially turbo engines. So how do you know the engine temps were a little higher...by the dash gauges or by a scangaugeII? Dash gauges are notoriously inaccurate.

I would look to do an upper grill block and look at other avenues like a belly pan, pizza pan wheel covers.

Thanks leanburn, yep I think I will just improve other areas, especially coming into Summer. It was the engine temp guage on the dash, it usually sits around 81°C and on this occasion it went up to about 90°C.

I second the upper grill block and leaving the lower as is. Wheel covers, rear wheel skirts, and a belly pan would help quite a bit I bet. Besides that, it looks like the lower grill isn't *that* large compared to other cars.

You don't have to do a full block on the bottom. Just like NASCAR...you have to determine the opening by either using calculation or by trial/error methods. You may want to consider building some ducting so the air that does enter the opening gits directed straight to the cooling fins and doesn't git detoured somewhere else. :D

I would install an under the hood thermometer (digital meat thermometer would work) to see what temps you are gitting under there. I would establish a base line before you start blocking so you can see what's going on under there first. ;)

As said, don't block off the grille to the intercooler.
You may get away with it in winter, but as temperatures increase it'll need the cooling.

Then again, 90° water temperature shouldn't lead to smoke coming from under the hood.

A question from a non-turbo guy:

In a situation like this, would it be a good idea to change the oil, just in case?

Turbodiesels like warm temperatures but cold intake air. In my Pug the radiator side of the grille is blocked, but the intercooler side is left open. No problems with that.

When have you last cleaned your engine bay with some good pressure washer and oil stain remover stuff. There might just have been some dirt and oil which start to "burn" when no cold air is coming to the engine bay. Engine undertray usually soaks in oil and other "flammable" material and you should clean. There is usually some material which soaks in any oil that falls from engine.

On my lupo I have removed my intercooler totally, so you dont need it necessary on speeds under 120 km/h. There has been non intercooled diesel cars long time and they dont "have" problems with intake temps. On my Lupo intake temps are under 50 celsius in normal driving. With intercooler they are 20-30 celsius lower. So intake temps are higher but that is not the cause for smoke from engine bay!

You might also have oil inside your intercooler. So you should check and clean that also.