Just need an opinion....

[BigJohn82]

My Durtle seems to run fine overall. However every now and then while sitting after driving at a stop like in a drivethru like tonight at taco bell it seems almost like the idle is rough. Its always idling at like 600 never below once fully warmed and only higher on first start of the day til she gets warm. While sitting at the drivethru I turned my music off and just listened to the engine while I sat waiting for my food(which was good btw), and it seemed almost like it was kinda going up and down a little bit because the sound the engine was making wasnt the same constant. I was watching the rpms and it never moved at all. Any idea if this is considered maybe a rough idle or what could it be?

Also when im speeding up slowly and listening to the engine I hear what to me(the best I can describe it) a sputter like sound. I dont know how else to put it. I dont know what it is. Maybe its air going into the t-body since I removed the rubber flap at the radiator and took that front tube off the factory air box to get more air in til I make my custom intake this weekend but its kinda annoying. Again this is another thing that wasnt there when I first bought her. Any suggestions?

Another thing is lately im getting a slight sqweel now and then from the rear when I push the gas slightly while making a turn slowly (almost like tire sqweel). I think I should have the rear diff changed and maybe thats what is making this sound. What do you think?

Lastly, I gotta go change my oil tomorrow. I was told that switching to synthetic oil at this point since I have 107k miles on it that it could do more harm then help as in burning oil or whatever. What do you guys think about this? Would it still be beneficial to switch at this point or should I stick with 10-30w high mileage oil(had this used last two times)? Lemme know what you think cause its getting done tomorrow hopefully.

Thanks to anyone that replys with some suggestions on any of these. I value all help given by anyone.

John :D

[coachholland]

Can't speak for sure regarding the first two problems. I think you're on the right track regarding both issues though. The rear may need some new lube and the if you took something off the airbox, your replacement will likely clear up the problem. Might want to check your plugs too though and see if they're starting to foul out. Then again, it could just be bad gas.

When you're using dino oil for most of the vehicles life and then decide to change synthetics, you starting noticing problems that may not have been noticable before. You may develope an oil leak, perhaps a tad of a knock, stuff might start leaking past seals. Is it the synthetic that caused that?

No, of course not. The deal is that synthetics don't have the build up and they will clean your engine better than the old stuff. Dino oil will mask some things by gunking up stuff, thus you don't notice the problems that will cost you a little bit now until it is too late and costs you thousands later.

It will *not* hurt your engine to change out oils, no matter how long you've been using brand or type "x". Going to a cleaner oil will simply get your engine cleaner which may show you problems that you didn't notice before. I feel that the best transition that can be done when going from dino to synth is to go with a good blend, such as Mobile High Mile blend (don't recommend Pennzoil because it's not a true synthetic) for a couple of oil changes and changing it out every 1500 miles. Then full synth and change it out at another 3000 miles then have your engine flushed. The synth blends and full synth will break down a bit of the gunk at the miles stated, but not enough to free it up in one place and gunk up another part. The flush should break down the majority of the rest and you should be good to go. I would still say to change out the full synth every 3K for a couple of changes before moving on to the 5K oil changes that it allows.

[Almond Pale Ale]

I agree with the oil recommendation above, Mobil is a good brand.

Your idle will fluctuate if you have the A/C on or the defroster, the A/C compressor will switch on and off and the bumps the rpms slightly.

Removing that front rubber flap won't add sound. The front tube might but keep in mind, that cold air intake will add more sound than what you have now, you'll hear some good "sucking" noises. I wouldn't worry about the noise b/c your CAI will be a big surprise noise wise.

For the rear end - do change the diff fluid. It's easy to do and cheap insurance. Also - check your rear suspension bushings, the rubber does wear out and it'll squeak. My front right sway bar bushing squeaks going over a speed bump. Use Silicon or LIthium grease (not penetrating oil or WD-40 - petroleum brakes down rubber) to lubricate.

[BigJohn82]

Coach: Thanks for all the info bro. As far as the plugs fouling out or anything I doubt thats possible since I just put brand new ones in like 5-6kmiles ago. I think I will hold off on switching to the syn for time being and wait another oil change or two and do as you suggested when I do change to it. However is an engine flush needed when doing this? Whats the engine flush do and how much would it run? Moneys tight so I need to know ahead of time what im getting myself into which is why im not going to change right now.

Kevin: I never use the a/c unless my girl is with me. I never use the defroster period lol. I just put my windows down no matter how cold it is outside and go from there. Also when I go over speed bumps it does make some squeeky noises so I probably do need to lube stuff up. I should try to do this differential change on my own because its about 50 bucks to have it done anywhere. Ill see if my dad can help me do it sometime soon.

Thanks for the help guys.

[coachholland]

You can get some engine flush from your local auto parts store. Basically, you run it for 15 minutes and it breaks down the gunk built up in your engine and hopefully puts it down in your oil pan to drain out. This is especially useful for sludge issues. Not for certain on the D's because I've never done it, but as a boater, we will occassionally also use a product called Seafoam to decarb the engine and get rid of carbon deposits built up. Seafoam will work on autos as well. The thing to remember is when you do it, make sure that your exhaust isn't up against anything that you don't want to get dirty. Black crud will get all over everything as the carbon breaks down.

The reason for the pre-use of synths and synth blends is that it will start the cleaning process and there will be less gunk to clean out on when you flush the engine. Less chance of just pushing all the crud to another part of the engine or needing to flush more than once.