Does anyone know if the EGR to Intake pipe is negative or positive pressure.

As both the exhaust gasses and 'turbo fed' intake are above atmospheric pressure, I am sure that 'the 'cooled recirculated' gas in that pipe is above atmospheric pressure as well.

Exhaust Gas Recirculation (EGR) System
Harmful nitrogen oxides (NOx) a constituent of the exhaust gases, are formed by the reaction between oxygen and nitrogen at high temperatures. Reducing the engine's combustion temperature and therefore the amount of NOx produced is achieved by recirculating a proportion of the exhaust gases. The recirculated exhaust gases replace some of the engine's intake air as this reduces the oxygen content within the cylinders and lowers the peak combustion temperature by several hundred degrees.

To reduce the temperature as well as increase the density of the inducted fuel charge, the recirculated exhaust gases are passed through the Exhaust Gas Recirculation (EGR) cooler. The EGR cooler utilizes coolant from the engine cooling system to reduce the exhaust gas temperature. Exhaust gases entering the EGR cooler reach temperatures of approximately 500C; the EGR cooler lowers the temperature of the gases, to 250-300C before they exit the cooler.


The EGR valve and cooler assembly is located on the RH side of the cylinder head above the exhaust manifold, and secured with 4 fixings. An inlet pipe connects the EGR cooler to the exhaust manifold. A gas transfer tube is routed across the engine and connects the EGR valve outlet to the intake manifold housing.

A pipe on the EGR cooler body connects to the climate control heater outlet hose, and provides the coolant supply to the EGR cooler. The EGR cooler outlet connects to the coolant rail, located on the RH side of the engine. The coolant rail is connected between the thermal control module and the coolant pump rear housing.
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Thanks Ian. I am wondering if the EGR delete blanking plates produce an excess pressure in the crankcase?

I don't see how it could do that - all the blanking plate does is keep the exhaust gases in the exhaust where they belong.

The EGR pipe would have to have positive pressure relative to the intake, otherwise it would work backwards and suck intake air into the exhaust.

I Like Chips wrote:

Thanks Ian. I am wondering if the EGR delete blanking plates produce an excess pressure in the crankcase?

Hi Ian about two years ago when I first bought the motor, I tried blanking off the pipe using a drilled EGR delete plate off e bay. After around a thousand miles I noted that there wasn't any real benefit so removed it.

About a year maybe nine months ago I noticed engine oil at the back of the engine. I thought it was coming from the plastic air pipe connection at the top of the engine cover, I discovered it wasn't but it was something more sinister.

I was advised by a local Indie that it was a leak from the rear crank seal. I had this renewed with success apart from the cost of course.

I find myself wondering if the seal "went" because of excess pressure in the crankcase due to the fitment of the blanking plate. Just an idea really?