View Full Version : TR6 TR6 oil looks dirty soon after change...

05-25-2007, 04:09 PM
I'm noticing my oil looks pretty dirty (at least darker)soon after fresh oil changes. I know this could be for a couple of reasons, but I'm thinking maybe I'm running too rich, b/c my gas mileage has also decreased. How exactly do I lean out the mixture? Thanks for any help.

05-25-2007, 07:39 PM
The 'official' adjustment is down inside the dashpots and takes a special tool to turn. The tool is readily available (and cheap); basically just a long Allen wrench with an aluminum sleeve around it.

However, I would suggest first trying to find out what changed, as it's unlikely the adjustment moved itself. Could be a torn diaphragm, leaking float valve, crimped emissions hose, or possibly a failed thermal compensator (just to name a few).

You should also recheck the valve lash before setting mixture. Oh yeah, be sure the chokes are returning fully off, too.

05-25-2007, 07:52 PM
I've a TR3 and not sure if you have a mechanical fuel pump or electric. If Mechanical chances are your diaphram is leaking fuel into the sump and contaminating the oil. It doesn't take long for this to happen and is common when the pumps are not regularly refreshened.

05-25-2007, 10:30 PM
If it's running well, just don't mess with it. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif I'm a great believer in if it's not broke, don't fix it. Maybe by getting better gas milage you have to sacrifice hours of tuning carbs.. Weigh the trade off.

05-26-2007, 12:19 AM
usually when fuel is diluting the oil the color is lighter than darker, the viscosity lessens also, and the oil on the dipstick will be smelling of petrol, also detected nacrally by removing the oil fill cap and sniffing.

05-26-2007, 09:56 AM
Oil gets dirty from the blow by around the piston rings. This usually worsens over time. A sudden decrease in gas mileage, assuming you did nothing but change the oil, and a more rapid dirtying of the oil could, might indicate a ring problem. To rule this out, do a compression check on each cylinder.

If all is well, drive it.

05-26-2007, 11:22 PM
The car does run like a top. I'm a new "older car" owner, so maybe you guys are right, it's just something I'll live with. Thanks.