bym007

Hi all,

My car recently had some cooling issues, as the weather is getting hotter in Saudi Arabia now. After diagnostics, here is what we found out:

The diagnosis software is showing the temperature for engine raises to 107'C, when the cooling valve should open and allow the coolant to circulate in engine (Coolant temperate sits at about 55-58'C). This valve is apparently not opening everytime the engine temperature raises beyond the threshold. When it does open up, the engine temperature drops to around 100-103'C mark, and the coolant temperature as a result raises to 60-70'C approx.

The Indy mechanic (ex-BMW dealership) wants to replace this valve. Can someone kindly confirm if this is correct diagnosis. Also what is the part number for this valve?

BimmerFan52

Thermostat - 11537549476
$75 - 120 for part depending upon where you buy it.
Couldn't guess on labor rates over there. Some good DIYs on the forum if you are so inclined.

bym007

I am reading somewhere, some people suggesting to replace EGR and then some replacing the main thermostat. I am quite confused by this.

Can you also kindly confirm the diagnosis as well as which thermostat part # have you suggested? For labour, I will head back to my Indy as I am not very good at mechanics

BimmerFan52

You described your problem as occasional overheating of the engine due to restricted coolant flow.

The only two components that control coolant flow in the engine are the water pump and thermostat. The thermostat acts as a valve and releases water to circulate through the engine once the wax in the thermostat melts (when the water reaches the temperature the thermostat is designed for) and the valve opens. The belt driven pump on your vehicle continuously pumps water which is circulated through the radiator until the thermostat opens at which time the engine block is included in the circulation path.

The EGR (exhaust gas recirculation valve) recirculates a portion of your engines exhaust gas through the engines combustion process again to insure complete burning of fuel and a reduction of emissions. A sticking EGR can result in rough idling or poor acceleration but does not affect cooling of the engine.

Your Indy can make a final diagnosis and will confirm the part number when he orders it.

bym007

Thanks for the clarification mate. Indeed, the engine is suffering from occasional heatup, and then throwing up warnings or errors for short periods of time (10-120 seconds), until it cools down again. This has not happened in last 2-3 days though.

I changed my water pump a couple of months ago, so I believe that is good to go.

From your comments, I can safely assume that the issue is thermostat, and not the EGR. Thanks. I will keep it in mind when talking to the Indy.