Diesel_Aggie
Veteran Member
I hope my 1.6NA question is welcome here! I have an '81 Caddy with a 1.6NA diesel that recently started blowing oil out of the dipstick tube. Mileage is unknown and the year of the 1.6 is unknown but it is mechanical valves. I bought the truck 2 years ago. It sat for most of the first year and has been driven for the last year. The last 6 months it has been a daily driver. Oil consumption has been a quart every 1200-1500 miles prior to latest problem. At 60-70mph at 3600' elevation there has always been light smoke blowing from the tailpipe going uphill or into a headwind. Seems to be black diesel smoke. Starts up great in single digits. 5000 miles back I switched to Rotella T 5W-40 synthetic. It was about 3000 miles into this the oil started coming out the dipstick. It did it once on a 700 mile highway trip and stopped. I didn't know where the oil was coming from so i cleaned it up and it didn't leak for maybe 1000 miles or so. Drove it to Dallas and it started leaving big oil drips on the ground. Suspected the dipstick, cleaned the area and confirmed. Changed oil/filter today, cleaned and after driving 5 miles you could see oil streaming down the dipstick. Pulled the crankcase vent hose from the valve cover to airbox. It is not obsctructed but is wet with oil. Started engine with line removed from valve cover. Lots of blowby coming out of this hole and out of dispstick. You can see the oil drops coming out of the dipstick but not the valve cover. Pulled the hose from the vacuum pump to the engine block at the vacuum pump side. Tons of blowby comes out of here when it is off. When it is off the quantity of oil coming out of the dipstick is less as is the blowby out of the valve cover and dipstick. Plug is with your finger and it goes back thru the other areas.
I spoke with Parts Place Inc. briefly and they suggested trying a German oil filter instead of the Napa Gold/Wix I've been using. I'll get one this afternoon but I've been running the same filters for the last 15,000 miles with no issues until now. They also suggested that there is a port/vent on the oil pump that may be clogged. Can anyone elaborate on this and what to look for? My Bentley is not with me unfortunately. Parts Place felt that it was not rings as I was worried about and said to put a manual oil pressure guage on it. I'll try and find a guage this afternoon as well. Truck starts immediately and seems to have normal power. I do not have the extra under valve cover piece that I have seen discussed in some forums. I can believe that the switch to synthetic freed up a bunch of crap in the engine and that it is plugging something up.
What is causing the oil to blow out?
Where do I put the manual oil pressure guage on the engine?
What do I look for on the oil pump?
What is the purpose of the tube from the engine block to the vacuum pump?
Thanks for the help.
I spoke with Parts Place Inc. briefly and they suggested trying a German oil filter instead of the Napa Gold/Wix I've been using. I'll get one this afternoon but I've been running the same filters for the last 15,000 miles with no issues until now. They also suggested that there is a port/vent on the oil pump that may be clogged. Can anyone elaborate on this and what to look for? My Bentley is not with me unfortunately. Parts Place felt that it was not rings as I was worried about and said to put a manual oil pressure guage on it. I'll try and find a guage this afternoon as well. Truck starts immediately and seems to have normal power. I do not have the extra under valve cover piece that I have seen discussed in some forums. I can believe that the switch to synthetic freed up a bunch of crap in the engine and that it is plugging something up.
What is causing the oil to blow out?
Where do I put the manual oil pressure guage on the engine?
What do I look for on the oil pump?
What is the purpose of the tube from the engine block to the vacuum pump?
Thanks for the help.