High EGT's

Hi all, I'm looking for everyones opinion. I have a GUIII 2003 zd30 auto with dawes valve, EGR blocked, catch can installed. For the last couple of weeks I've noticed a distinct lack of low down power and a hissing coming from the engine bay only when under boost. I've also noticed the EGT's get high very quickly and a little higher than normal on the highway - 320 instead of 280deg. Also noticed a little puff of light grey smoke on start up and at night in the head lights of the car behind me when I put the foot to the floor after the light goes green. I still have the original ic and hoses and gave it all a very good clean when I first fitted the dawes and everything, I didn't replace it due to funds and there was no sign of it leaking.

I took it off today to find it is now leaking and suspect it's causing all the problems including the light grey smoke but I also found it wet with oil below the injectors and around the front glow plug seal. The oil around the front seal is directly below the worst leak on the intercooler. What does everyone else think.

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A very good chance its leaking [intercooler] being in a 2003 model also the rear hose has a tendency
to pop off. High EGTs are from too much fuel and low boost. I reckon you go get a tigged intercooler
and set the dawes to 10psi at 100KPH and your problem will be solved , also fit a catch can.
Another reason could be a dirty maf, grab some MAF cleaner and give it a good spray dont
touch with your fingers. While you clean the MAF disconnect to battery while you do it as well
Check all those small vacuum hoses as well

I've already fitted a catch can and set the dawes to 10psi at 100 kph and I clean the MAF sensor and reset the computer every 5000klm when I service it. I checked all the IC hose connections and checked for splits everything seemed to be good. I did notice all the vacuum hoses under the IC where quite hard so i'll look at replacing them all when I do the intercooler.

Do you think the oil on top of the motor is from the IC as well?

Quite possible its a fine mist that eventually will settle.
How oily was inside of the IC
They dont like being over filled [oil] just under is ideal.
Hissing noise no idea at this stage

The IC and hoses had a reasonable amount of oil, nothing like it was when I first fitted the catch can and cleaned the system out. When I service the car I always replace the oil filter and the put 8.2L of oil which is about halfway between the 2 marks on the dipstick. I'm thinking the hissing is the leaking IC. The tigged IC that I'm looking at also comes with new hoses so hopefully with that and the new vacuum lines all my problems will be fixed.

Well just as a test I thought I'd re-crimp the factory IC and the car now has its responsive low down acceleration and the little puff of smoke on start up and hard acceleration has gone. Tigged IC and new hoses looks like will fix the problem.

How'd you go with the intercooler upgrade? Mines leaking from all 4 corners and an upgrade is on my wish list but I really need to justify the cost. My egt's run anywhere up to 560c on up hill runs and generally around 380-400 on the highway. That's CRD by the way.

Cheers,
Drew.

I know it's an old thread but a good degrease at the car wash would help to spot leaks, especially those in the induction tract.
Unless the catch-can has an actual element or material to condense the vapour, the can is useless. This is very common with cheapies from the shops like AB, SC & RC as well as eBay. The only CC I have seen that meets the grade are the ProVent units or those custom made with stainless steel-wool inside.

10PSI @ 100 WILL see 300°+ on flat highway with no weight on-board.
14PSI will see it drop to 250-270°
Bigger and better IC will see drop in temps as well.
16-20PSI on cruise is way too high and just overheating the inlet charge temps as well as unwanted back-pressure on the exhaust side.

Good reason my needle vale is IN the cabin.

Yeah the new intercooler and hoses seem to fix the problem I had.

hissing is boost venting in most cases .....
on hillls if your engine temp is rising lift you right foot a little you will hear the change and see the engine temp drop