oil on water pump housing bolts - PeachParts Mercedes-Benz Forum

jorjordandan · #1 10-23-2021, 08:40 PM

short story - I removed the waterpump housing on my 1981 240d and there was oil on the 3 right most bolts. The oil seems to be down in the threads, I did not use any penetrating oil to remove them. is this normal, a huge problem or... something else? It got dark before I had a chance to really dive into it so im going to look closer at it again tomorrow but wanted to reach out here first.

Long story - Ive had the car about a year now with out having to do anything too major to the motor, it only has 83,000 on the clock (which based on the condition of everything I believe to be true). I took it on an 8 hr road trip 2 months ago, changed the oil and gave the motor a good cleaning before I left. 20 minutes from my destination I stopped for fuel and noticed a small coolant leak, temp had been constant the whole drive and this was 90 degree weather from Texas to Oklahoma 75 - 80mph the whole way. I got in late, parked the car over a pan and checked it the next morning. leaking from the water pump. I left the car in OK, flew home and flew back with new water pump and thermostat. when I pulled the waterpump housing the first time I used penetrating oil, bolts came out fine but when I pulled the same 3 bolts it looked like there was motor oil on them. I chocked it up to everything being caked with years of grime and figured that just what it was. on the drive home I developed a leak at the small 2" hose below the thermostat. I didnt order any new hoses the first time but ordered everything once I got back and dug into it this weekend to basically re-do everything with more new parts. Now I take those same bolts out and again there is motor oil but this time I didnt use any penetrating fluid... what's the deal? is this ok or terrible? or does this not make any sense and maybe I should just clean the bolt holes really good.

jorjordandan · #2 10-23-2021, 08:47 PM

photos here:

[IMG]https://ibb.co/gTZvZXF
https://ibb.co/Mg810SB[/IMG]

also... im new here, how do I post photos into the thread?

Sugar Bear · #3 10-24-2021, 12:29 AM

It's fine, the bolts protrude into the timing chain cavity. You could clean them very well and put a SPARING, SMALL amount of sealer such as Aviation Form-a-Gasket on the threads to prevent an oil leak. Don't load them up with silicone, excessive sealant could find a way into the engine. This would be unlikely but why do it?

Good luck!!!