Help yet again with 98 Grand Caravan! =(

Messages
9
Location
Long Beach
Okay, this is a weird problem and I hope you guys can help. I switched from 5w30 to 10w30 when I moved to California because at all the places you go to it seems like 10w30 was the standard at all the places. In particular at a place called Tune up masters that I went too in long beach. They only use Castrol oil and at the time that's what I always had a preference for but then I started to notice that I was getting some pretty awful MPG for some reason. Then I had a short in the electrical system and me not really having any mechanic friends yet or knowing anybody in the california area to trust as my mechanic I had to put it into a local place called Sams. They then told me that my front valve cover gasket was messed up, and that my oil pressure switch was also broken. They said my car smoked for them and it made them hard to see if anything else was wrong. And I think that was crap because my car never smokes for me, not even after I took it from their shop. My neighbor back in St.Louis who is a mechanic kind of laughed when I told him what they said because he looked at my car right before I moved and said they just wanted to get more money out of me. My car is now at 101,300 or so miles and so I guess I am getting a little bit worried about engine problems and wanting it to have better protection and better MPG. I officially decided that maybe I should switch it to a Synthetic Mobil brand because everybody tells me that I'll get better performance, protection, MPG... the whole 9 yards. And it also seems to me that a lot of people here at the forums like synthetics over regular dino oil and people have told me before from the board that it wouldnt hurt my car to switch from dino to synthetic. What would you reccomend I use considering all of the above information? I really value all of your opinions and help from this board. Also on a side note, my car has an oil leak.. it has for over 2 years. But it's the strangest thing because it drips like maybe 2 to 3 tablespoons of oil a day for 2 days.. then it stops leaking and you never hear of the problem again. You can check the dipstick and everything is fine its not like those horror stories or anything of people needing to add a quart constantly. That whole leak thing is weird to me so I figured I would share it with all of you. Please inform me of your opinons on what type of synthetic oil I should switch too!!! Keep in mind too I only have access to like Autozone or Kragen so I cant find that fancy german stuff you guys all like too.. thanks!!! Siege [crushedcar] [Cheers!]
 

Siege

Thread starter
Messages
9
Location
Long Beach
Also since I typed pretty confusing like, before anybody asks.. no I didn't pay to get anything with the valve cover gaskets fixed since I also personally never noticed or seen anything wrong. I really didn't want to trust them with my car after dealing with a mess for them to fix my electrical system short so I paid to get it running again and got the **** out of their!! [Big Grin] That was just to save time of people not being able to figure out if i actually was conned or not. Siege
 

Al

Messages
19,160
Location
Elizabethtown, Pa
First of all-I would try to get to the bottom of the problem. The Pennzoil 10W-30 compared to the 5W-30 would give you a 2-3% increase-if that. What that means is that if you got 20 mpg you would get maybe 20.5. The Syn won't make a whole lot of difference (if any). Did they fix the valve cover leak?? What about the oil pressure switch? I would get those problems resolved first at a dealer type place vs the local schmuck-unless you know he does good work. Doesn't sound like the one you have does. If you decide to go the Synthetic route- Mobil1 1 10W-30 in Cali would be good all year around. But again- the biggest advantage for synthetics is longer drain intervals. Good luck. Keep us informed [Smile] [ September 15, 2003, 09:36 PM: Message edited by: Al ]
 

Al

Messages
19,160
Location
Elizabethtown, Pa
O.K. So you didn't trust 'em. I can't really blame you [Smile] Hopefully someone will have more input. But I would like to see the oil leaks stopped anyway [Big Grin] And let's hope your oil switch is O.K. [Smile]
 
Messages
8,711
Location
Nothern USA
I would guess any big drop in mileage is from other than the grade of oil unless most of your driving is short trips that never warms the engine up. Oil pressure switches are fairly easy to change and Auto zone and Kragen should have them. Ask around and see if anybody know a better place to have work done. To be sure on the mileage, you might track down enough 5W-30 for your next oil change. If it doesn't go back up, look for another cause. If you are putting in hard or extended highway miles, synthetic and longer drain intervals might make sense. Since I don't put too many miles on, I stick to frequent changes of dino. If you do go synthetic, check Wal-Mart for Mobil, or even Super Tech. I would also keep an eye on the oil leak. Also check all the hoses and PVC valve.
 
Messages
301
Location
SE Michigan
"I was getting some pretty awful MPG for some reason." What about the gasoilne out in CAL? I hear that some parts of the southwest and CAL have "cleaner" gasoline that just doesn't get good MPG........
 
Messages
39,806
Location
Pottstown, PA
quote:
"I was getting some pretty awful MPG for some reason." What about the gasoilne out in CAL? I hear that some parts of the southwest and CAL have "cleaner" gasoline that just doesn't get good MPG........
Yes, I don't think that you would experience a radical drop in mpg without some other symptom. That is, hard starting ..missing..hesitation ...etc. Here in PA, if you're in a selected "emissions county" ..you have oxygenated fuel. Some cars handle it without degradation ...others use up to 25% more of it to go the same distance. They've actually found that because of this ..it actually causes more pollution since soooooooo much more of it is used (it only reduces emissions 10%). It's continued use is probably because there was a "so many year" commitment of use for the development of the cleaner fuel to the refiners by the government. Are you sure this is not because of the geographical location/fuel source??
 
Messages
508
Location
milwaukee
Is it possible you have run normal gas for 100k and now run oxygenated gas? If so the new gas may be causing chunks of varnish to break off in the fuel system and cloging things up. My truck was run for 28k on regular gas and I live in MTBE country. I used Neutra to disolve the varnish remaing in the system. It seems to have done some good becaue my gas mileage is getting better.
 

vvk

Messages
481
Location
Philadelphia
I think that the repair shop meant that they can't use a gas analizer on your van because of burning oil. The results would be incorrect. They are simply trying to diagnose the problem. Obviously there is a problem, since you talk about worse fuel economy and electrical glitches. The fact that van was in good shape before your move does not mean that there is nothing wrong. You should go to a competent mechanic (look for one who charges high prices [Wink] ) and have the problem diagnosed and fixed before doing anything else. As far as switching to synthetic. I think that this is a bad time. You have a problem that needs to be fixed first. Using synthetic oil will not take care of that. It will only make you spend more money on oil. I think your leak will get much worse if you switch, since right now it is probably held by oil grime which will be cleaned away by synthetic oil. Fix your oil leak and pressure sensor first. Having a broken oil pressure sensor is dangerous. You can loose your engine [Thumbs Down!]
 

Siege

Thread starter
Messages
9
Location
Long Beach
quote:
Originally posted by vvk: Fix your oil leak and pressure sensor first. Having a broken oil pressure sensor is dangerous. You can loose your engine [Thumbs Down!]
The oil pressure sensor isn't broken, at least I don't believe it is. Also their was no valve cover gasket problem, remember the mechanic was just trying to screw me? And as far as the different types of gas go. I've noticed by far that here in SoCal each place gives me different performance. Shell is #1, followed by Mobil at #2 and Chevron at #3. So depending on where im working at that day when I get gas, It's from one of those three although I should probably just stick to straight Shell gasoline. How could I tell if the oil pressure sensor is broken? All the instruments in the dashboard work properly. I've tested my car in both hot and cooler times and everything performs and works as normal.
 
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