Repair on head gastek

cts_casemod · 24 October, 2022

Hi Guys,

Spoiler: renault engine here -:)

Recently car developed an oil leak into the coolant. It doesn not seem like the oil in the sump is contaminated, but there is a layer of oil in the expansion vase and to a much reduced ammount coolant ways. Coolant came out clean, as per picture (any debris there is from standing outside two days)

I stopped driving the car as soon as I noticed the issue, so have no further history, no horrors and no ill simptoms, other than the oil observed on the expansion tank.

Facts:

- There is slight corrosion on the coolant water ways and what seems to be a gasket hole that leads to no channel on the head.

- I measured with a 0.10mm tool and there doesn't seem to be any signs of warpage in the head up to that level.

- The Valves are not sealing right, both intake and exhaust, but exhaust is worse.

- The intake is heavily filled with soot, due to a sticking EGR

- The head will be taken to a machine shop to grind valves, replace seals, ultrasonic cleaning of head and manifolds and possibly resurfacing.

Questions:

- Should I re-skim the head to better make the coolant ways seal against the gasket or would the ultrasonic cleanic suffice? The gasket is 1.5mm thick which leds me to believe the engine was never opened, but I would rather keep it as stock as possible

- What is the best way to clean the engine block, before the new headgasket? I would thought sanding it, but afraid of any contamination inside the cylinder

- The engine is 270.000Km. The valves were checked to leak by pouring some WD40 and observing fuid slowly seeping through to the other side. The vehicle worked ok with no smoke, but cold idle was shaky with the ocasional misfire. Main question is - should valves be replaced or just have the machine shop grinding them and replace the oil seals? What about the valve seals on the head?

Thanks for any help. Pictures follow.

Pictures:

Intake port (wetness is oil seppage when testing valves)

Exhaust:

Intake valve, open:

Head. In between cylinders - Coolant channels with no path on the head. Pitting observed. Minor pitting also observed on the coolant channels themselves.