-
#15
by
burn_your_money
on 06 Sep, 2012 19:29
-
I don't think that's going to tell me anything, unless my compression tester is completely wrong ( but my ear tells me it's not since the engine starts so well).
Advanced timing can easily mask compression issues. I wouldn't assume the compression is good because the car starts well. There's a reason a lot of people on the site time their motors above 1.00mm
Like you said though, a leak down test isn't going to show you much. Valve stem seals can be done in the car so that would be a nice easy/cheap place to start.
-
#16
by
R.O.R-2.0
on 06 Sep, 2012 22:27
-
I don't think that's going to tell me anything, unless my compression tester is completely wrong ( but my ear tells me it's not since the engine starts so well).
Advanced timing can easily mask compression issues. I wouldn't assume the compression is good because the car starts well. There's a reason a lot of people on the site time their motors above 1.00mm
Like you said though, a leak down test isn't going to show you much. Valve stem seals can be done in the car so that would be a nice easy/cheap place to start.
valve seals can make ALOT of blowby in an otherwise TIGHT engine..
-
#17
by
theman53
on 07 Sep, 2012 06:02
-
I don't think that's going to tell me anything, unless my compression tester is completely wrong ( but my ear tells me it's not since the engine starts so well).
Advanced timing can easily mask compression issues. I wouldn't assume the compression is good because the car starts well. There's a reason a lot of people on the site time their motors above 1.00mm
Like you said though, a leak down test isn't going to show you much. Valve stem seals can be done in the car so that would be a nice easy/cheap place to start.
valve seals can make ALOT of blowby in an otherwise TIGHT engine..
That is what I am talking about. They can be torn or worn and you will lose a ton of oil.
-
#18
by
rs899
on 07 Sep, 2012 11:47
-
I guess I was under the impression that since a diesel has no natural vacuum, valve seal leakage was pretty minimal.
It's worth considering. I don't know how fiddly it is, though. I can barely get those keepers to cooperate when the head is on the bench.
I suppose you mark the flywheel or front pulley so you know where TDC is for all cylinders and have at it? Anyone done it on the car?
I just know if/when I try that I will find that the guides are real sloppy and then....pandora's box...
-
#19
by
libbydiesel
on 07 Sep, 2012 11:52
-
I can imagine a pretty good gale of wind blowing up the valve stem from intake or exhaust manifold pressure if the stem seals were shot, but the pressure would send the oil out the crank vent rather than into the engine to be burned. If you are already running to a catch can, then I would think stem seals might not make much of a change. they're not going to hurt, tho.
-
#20
by
hillfolk'r
on 07 Sep, 2012 21:29
-
use some nice snotty grease for those pesky keepers..put it on em..and some on the valve stem too...stick em in place.just a lil hillfolk tip
-
#21
by
rs899
on 08 Sep, 2012 04:11
-
^^ Not so much that, but getting them oriented and seated on the stem in that little space while crunching down the spring. PITA.
-
#22
by
DogDiesel
on 08 Sep, 2012 06:46
-
I have own a lot of these 1.6 & 1.9 diesels. One topic I am not seeing discussed is coolant temperatures.
I find that when I control the coolant temparature (and with a coolant based oil cooler) and therefore my oil temperatures, my engine do not use oil.
First start with a coolant blend. Water boils at 212 degrees Fahrenheit. 50-50 antifreeze will boil at 220. The recommended blend is 60% coolant & 40% water. 60-40 boils at 226 degree. 226-212=14 degrees.
Next for every 1lb of pressure added to coolant, 3 degees fahrenheit is add to the temp that coolant boils. Atipically the VW system uses a 7 psi cap. With tight hose connections and a good cap, the water would start boiling at 233 degree, 50-50 at 241, and the 60-40 would boil at 247 degrees.
So if 50-50 is 220 & 60-40 is 226, why not 80-20 or 100% antifreeze. Purer blend of coolant will affect the coolant based oil cooler. Blends above 50-50 and 60-40 will not cool the oil as well.
I have a 1.9TD in my Caddy, and the radiator is not large, because a big diesel radiator won't fit. My coolant temps are good. At first, I tried 5K mile oil changes and found no oil use. Then I tried 7K, and no oil usage. I now use 10K and still have no oil useage. I have all my diesels (10 vehicles) on a 10K oil change ritual, some on this diet for 200-400K.
Just did a 600 mile trip on I-95, running with traffic at 65-79 MPH and unless I gouged the throttle and stayed in it, my temp were just right of center. This oil change has 8500 miles and no oil useage.
We have to keep these engines cool.
-
#23
by
DogDiesel
on 08 Sep, 2012 07:01
-
Another topic I am not seeing clarified is oil. I assure you that unless the oil is designed for diesel, consumption will occur. Too thin oil will be consumed. I have 10 on road diesels and near the same number off-road diesels for my farm. I buy top quality good oil, and due to my climate locaton 15-40 blend.
I can take any one of my well performing diesels and change to a cheap oil or gasser blend and I would guarantee oil consumption. If I go to 18-20K on oil changes, there will be consumption.
Review:
1. Overheating - expect oil consumption
2. Poor quality oil - expect oil consumption.
3. Extended oil changes- usage.
4. Leaks. Fix them.
Name-brand oils for NASCAR will kill a diesel. Go to a truckstop. See what truckers use. Go to a diesel shop. See what they use.
-
#24
by
bajacalal
on 08 Sep, 2012 07:48
-
What kind of air filter are you running, OP?
I tried using a cheaper air filter and I got a massive increase in oil consumption, to where it would need about a quart every 500 miles and the exhaust smelled of burning oil. This was right after I refurbished my head and turbo, so I was worried that a seal was leaking.
I then put a German (Mann Filter, I think) filter back on it, and the oil consumption seems to have largely disappeared. The cheaper filter had noticeably less material and looked like it wouldn't pass nearly as much air, and it became dirty quickly because there weren't as many pleats. My theory is that the cheap filter increased the vacuum between the filter and turbo, which was enough to suck oil out of the valve cover, even with the plastic baffle there.
I'm going to try something else too, which I'll post later, that should just slightly restrict the airflow in the breather and trap oil mist.
-
#25
by
hillfolk'r
on 08 Sep, 2012 08:43
-
i didnt read all the posts after mine,but i like the 80c thermostat over the 87c...just my 2 cents.....
80c is approx 180f,and 87c is approx 195f....195 imo doesnt give enough thermal reserve for those long hot days up hills at wot...i used to have the rad fan come on at 70mph up long hills cruisin rt80 thru pa with an 87c,but no prob with an 80c
i had an aux fan switch paralelled with the stock rad fan switch,and the lamp would come on in the switch telling me the fan was running but not by my switch...
also...motorad makes failsafe tstats for our vws also...if they fail,they fail open.....
water cools better than af....ive seen too strong a mix cause an overheat...
i do prefer dex cool or an = these days.......
50-50 mix is ok,but 40% coolant is better imo,except you canada guys..thats good for- 20f freeze point.....
throw some water wetter in there also...
-
#26
by
libbydiesel
on 08 Sep, 2012 08:49
-
87° will result in better engine efficiency and will not cause overheating unless there is some other cooling system issue present. If there is some other cooling system issue, then the difference between the 80° thermostat and the 87° thermostat will mean an extra 1/2 second before boil over.