[Corsa B 1993-2000] Replaced X10XE EGR valve, refilled coolant carefully, now engine runs hotter...

[gb33]

Hi all,

A few months ago on the 'old' Corsa site, I ran into intermittent mild pinking issues on mild acceleration with my X10XE. Fast forward, it turned out to be an EGR that worked/failed intermittently, but never triggered any check engine light.

Yesterday I installed a new EGR, and after refilling with coolant (poured in at trickle) the car seems to run perfectly, with full heat coming from the matrix and both the radiator hoses getting hot at full operating temperature and no pinking. The water pump and thermostat are also both quite new (few thousand miles old) and showed no signs of trouble before the EGR replacement. Coolant has always been clean, with no previous neglect.

Unfortunately, the car just runs hotter than before. It used to stay pretty close to 92 Celsius most of the time unless it idled for several minutes or was crawling in slow traffic. Now it seems to easily run in the 94-98 range. I've drained and refilled the coolant successfully before, so I cannot figure out how it could have gone wrong this time. I also don't see any signs of leaking where I opened up the system (EGR valve and lower radiator hose).

Since yesterday, I've tried removing the reservoir cap several times whilst idling to try to burp the system (squeezing radiator hoses) to no avail.

Any ideas?

[Taurus]

Since the coolant sender for the temperature gauge is bolted into the EGR casing it's possible your new EGR is simply allowing coolant to reach the sender better, or it is making a better earth connection for the sender unit. They ought to run with the gauge around the region yours is now reading - eg the thermostat only begins to open at 92C so usual running temp is above that.

Unless the cooling fan is coming on too often I wouldn't worry. I suspect the gauge is just now more accurate.

[gb33]

Thanks again, Taurus. Yes, that makes sense with the earth to the temp sender being better, as the sender's exposed nailhead tip where the wire plugs on was oxidized greyish-black whilst the new one is shiny brass.

What a relief. I haven't had any problems with the fan coming on, so it seems to be ok as you say.