I have a 2001 GMC Savanna Conversion Van. 5.7 liter engine. It has 116,000 miles on it. I've used Rotella T-6 Synthetic (Group III) oil for the last 50k miles. 5W-40. Prior to that is was Amsoil or Mobil 1. The filters used were Hastings and then PureONE for the last 50k miles. Average mileage per oil change; 5,000
This vehicle is my tow vehicle for my boat (roughly 4,000 lbs). Used for roughly 5-6 trips per year. Otherwise, it is my everyday runner. Mainly short trips. I work less than 2 miles from home.
Over the last two years my oil pressure has dropped from 40lbs at hot idle to 25-30lbs. Under acceleration there has been no change. It continues to run at roughly 55-60lbs of pressure. It holds steady.
It uses about 1 1/2 qts of oil for every 5k miles. Part of that is a slight leak in the rear main seal. Mileage has always been poor. Maybe 14-15 mpg. Power is still excellent.
Auto-RX arrived here in 4 days. Very quick. I'm in MN. Gets pretty cold here and it's tough on Engines. Last week, with plans to start the Auto-RX program, I changed the oil to a cheap Group II oil and added MMO to start softening what is likely building up in my engine. I was able to get about 300 miles on it when the Auto-RX arrived. Already the oil was black. Drained the oil and replaced the filter. Oil; SuperTech (Walmart) 10W-40 weight. Filter; Purolator PureONE. Also new Air Filter and new PCV.
Second, added 6oz to my Transmission. Installed a Transgo shift kit at 50k miles. Went to Amsoil Transmission fluid. Nice, crisp shifting, but, I want to make sure it's clean. If you tow...put in a shift kit! I've learned that the hard way.
Added 4oz to my Power steering system. No problems there, just want it cleaned up. I'm using the Oil Burning" procedure because with this filter I expect it to load up quite quickly. I'm not expecting miracles. I'd just like to see some improvements. As it is the power is still exceptional. The engine makes no noise except in the dead of winter (-20) and there is a clacking at start up that lasts about 3-5 seconds. it's disconcerting for me. I think there may be a buildup in the oil passages. Either the oil pump or the mains. There appears to be no noise at all in the valve train.
I'm hoping to see an improvement in my hot idle oil pressure. That may only be wishful thinking. The mileage may be related to the Ring Packs. Not sure. Nonetheless, it's a big vehicle. I'm hoping for some results there.
Any input or insight would be appreciated. I'm going to do my very best to follow instructions to a tee.
Is it possible that the sending unit is not working like it used to? Sounds like you have always used good oil and maintenance intervals, although with 2 mile trips, I would have to change oil based on time and not mileage.
The main advice I can give you is to get that van out on the road and get some good, hot miles on it, while towing even. This is how you will get the most benefit from your Auto-Rx treatment(s). Short trips will not do much in the way of cleaning.
If you do not see the improvement in oil pressure that you are looking for, take out the sending unit and put in a real pressure gauge temporarily and measure it at various rpms and oil temps.
Actually, I use it more than to and from work. I'm on the Highway almost every day. But, I'd say a quarter of the time I just go to work then come home.
So, if I'm hearing you correctly, you're saying the more pressure I put on the system, the more the Auto-RX will be forced into the less accessable areas of the motor than when driven more gently?
I think you're also saying the hotter the motor is the more effective Auto-RX is? With this type of driving, will it not put even more pressure on my rear main seal and mains? I take it, that's a good thing?
As for the sending unit, I haven't really questioned it because it appears so accurate on the top end. It would seem to me that if it was failing it would do so across all engine speeds...would it not? I do know it is far more active than most similar gauges I've seen. Every shift, every change in rpm's it will show the change in pressure. Other GM trucks I've driven of late don't even indicate a change in pressure even when heavily throttled. So, maybe something is wrong with it.
Could it also be that the oil pump is partially clogged (screen or pickup tube)? This is what I have deduced from the way it responds. Could well be wrong though. Funny though, when it's not completely up to temperature it runs at 60lbs constantly, regardless of engine speed.
When I drained the oil/MMO combo a couple of heavy blobs fell from the drain hole. Could have been more too, I didn't watch the entire drain. I jacked up the front end to level the vehicle and made minor adjustments to make sure everything drained out.
Looking forward to watching this process to it's conclusion.
I don't put alot of faith in the dash board telemetry of modern vehicles. And I say that only because most are not mechanical, instead they are based on electrical sensors between a sending unit and a reciever at the dash. I have a 4.8 liter in my truck. Even though I do not experience such a wide fluctuation on the dash board telemetry, as you do, I am more inclined to beleive that your numbers are more accurate than mine. I see very small increases in oil pressure, running at full operating temperature regardless of engine rpm's. Mine reads about 60 psi at 2500 rpms and about 50 psi at idle. To me this is not realistic.
In any event you have the right product in the crankcase to resolve oiling system contamination type deposits. Positive impact on ring performance should occur in the first 750 miles of driving during the cleaning phase of the application. My 4.8 liter does a bit better in mileage when running the maintenance dose as opposed to no ARX in the system. Something to consider after you are done with your cleaning and rinse. My gains in mileage just from running the maintenance dose seem to be steady at almost a mile per gallon.
I will be running the maintenence program when I conclude the cleaning process. I'm expecting to have to run it twice. In fact, I'm running it twice (engine).
I ran it today for roughly 60 miles. I ran it hard and at 70mph on the highway. Checked the oil...dead clean, to be expected. It's slightly overfilled. Is this okay?
Also, I've already noticed it's running a little different. Could be the air filter and PCV. The PCV wasn't old but the air filter looked terrible. It's been a year and a half since that was changed. the hot idle pressure dropped to 20-25psi. A little concerned on that one.
Well, now it's a matter of driving and waiting. I'll get the boat behind it this weekend. We'll see how that goes.
Well, I'm at 350 miles now into the cleaning phase. All the leaks stopped today. I'm not sure if it's permanent but it's a welcome sign. I had a small Transmission leak too that has now stopped.
The oil pressure is now up slightly. At hot idle, in gear, it's now at 25psi. I'm pleased. I'm not even a week into this process and the results are already beginning to show.
Oil level is still a bit high. I guess it wasn't leaking much at all. Oil is still very clean. Clear as water. The dipstick looks brand new now. I'm wondering how the oil filter is doing (PureONE). Patience...that's the key now. Wait until mile 1300 and replace the filter. The Engine is running fantastic. The gas mileage already appears to have improved. 30 gallon gas tank, 3/4's used, 350 miles. For me that's an improvement of about 15%. I'm using premium gas and Techron so that may well have an affect too.
700 miles now. All oil leaks have stopped. Oil is still clear as water. Still full too. A little confusing too since I went through some oil before this process.
I'm going to clean the engine externally this weekend to make sure there are no others identifiable leaks.
Ran Permatex heavy duty radiator cleaner through my system last week. It created a torrent of leaks. I'm replacing the hoses, the water pump, the return hoses and the thermostat. Since running the Permatex the internals of the radiator (what I can see) look brand new. What came out of the radiator was awful. Lots of "sand" and a film that I can't even describe. It's been flushed over ten times now. That means run the water, drain, fill, take to the road and bring up to heat, return, cool, drain. I've got 5 gallons of absolute gunk.
So far the steering system has responded well. Nothing to report there. The transmission has had it's strange moments but it's settled down now. Shifting crisp and repeatably. The engine has also had it's moments. Some noise in the past week. Now it's back to dead silence. It's just running beautifully. Hot idle oil pressure is beginning to rise. Not a lot but any improvement I am pleased about. Maybe 22 psi. At 2k rpm it still runs around 50psi, maybe a bit more. Nothing new there.
I'll be switching out the PureONE filter at 1000 miles. It's a tight media so I'm not going to chance plugging it up. Then, the rinse phase will begin after 1500 more miles. Going to Rotella T6 for the Rinse (Class III). I've got a lot of it.
After completion I'll be running Shaeffer 9000 5W-40 oil and their #132 Moly additive. Adding a bypass filter too. I found an e-Bay seller for NTZ filters selling them for FAR under their market value. I want this engine to last. This time I'm doing it correctly. I'm switcching to an oversized Fleetguard filter along with the bypass system. Permacool Sandwich adaptor and a whole new approach to maintenence.
I guess we'll see where we go from here. seems like a nice ride so far. I've learned a lot about the vehicle. About other systems too,
Well documented it appears you have gone through some issues with your GMC thank you for using ARX. I have a 02 chrysler T/C and was looking at around $600 for the power steering pump installed it was quite loud I used 2oz of ARX that was in January and haven't had any issues.
You are so right it is very important to remove the ARX and add new fluid I went over the 1000 mile mark I just changed it out on Thursday the first thing I noticed was how easy the steering wheel was to turn I have a Chrysler T/C.
Daryl
-- Edited by dbdeland on Sunday 2nd of May 2010 02:57:29 PM