Archive for the 'General' Category

Running Diesel Engine With Vegetable Oil

Santiago’s question:

is it true that you can run a diesel engine on vegetable oil and a few drops of turpentine?”


Yes you can, but you don’t need the turpentine and you need to modify the diesel engine to use the vegetable oil. I just recently inspected a veggie oil GMC hippie bus at a Whole Foods Store. It had rows of huge filters, a pre heater to make the oil hot, AND a separate diesel only tank to start and shut the engine off. You can’t start an engine with vegetable oil, it won’t burn until the engine is already running. AND, you can’t shut off a diesel engine with vegetable oil inside it, because it will congeal like grease and clog everything up. SO, you must run the engine a little with regular diesel fuel before shutting the engine down to prevent this. Needless to say, this is a relatively complex set up, so don’t just go and pour vegetable oil into your diesel tank.

Car Braking Too Much Power Assist, Jerking Braking

Yuri’s question:

After extensive search I came across your site and decided to give it a try. I own this car for 7 year and never had a problem with braking. It was always precise. I see the red light or stop sign, I push the pedal depending on the speed and it always stopped where I knew it would stop. Lately, I noticed that with the same pressure on the pedal it stops about 10 feet earlier. Then I have to release pedal and push it again to make to the stop line. Besides, even at the low speed the car kind of pushes back heavily when it comes to a full stop. In other word, even I try to brake as soft as possible I’m getting a heavy push back which was never the case before. I don’t want to waste your time. I went to my mechanic who served my car all those years. Of course, the first thing he recommended to replace rear pads and rotors since they did have grooves. I did, but nothing changed even with brand new ones. He also checked calipers and said they work. Any suggestion? Thank you in advance.”


OK, you have a problem in the boost system of the car. It’s giving you too much power boost, causing the too fast braking and the vehicle to jerk when you do come to a stop. So, something is wrong with your power boost system, applying too much boost. Odds are the vacuum booster unit is going out and needs replacing, It’s not a really common Lexus problem, but it does happen occasionally.

New a/c compressor with receiver drier and the expansion valve

Louis’s question:

My mechanic tells me I need a new a/c compressor and in addition to that the receiver drier and the expansion valve. Why do these parts have to be changed if it’s just the compressor?”


OK, here’s why. If a compressor goes bad, it will often throw crud and possibly metal through the system. The expansion valve can collect this debris and then make the system not work after you put a new compressor on. The receiver drier also can collect this debris, AND anyway, EVERY single time an AC system is opened up, the receiver drier should be replaced because one of its duty is to dry the system of moisture. Once the system is opened up to replace a part, the drier collects all the moisture and is ruined. So, it should be replaced when even an AC hose is removed and replaced. Hope that explains it for you.

what is the best shocks available in the world?

Shahul’s question:

what is the best shocks available in the world?”


It depends upon the particular car you’re putting them on, and different companies makes shocks and struts for different makes. Bilsteins are among the best, if they make them for your model. Mikunis are excellant shocks for Japanese cars also.

Fuel Line Replacement for Rochester carb

Dave’s question:

Scotty I have a chevy powered motorhome 5.7 L V-8 4bbl carb, I recently bought a rebuilt Rochester carb for it, however the fuel inlet line is not in the same location and the original metal fuel line won;t thread in right because of a vac operated linkage in the way,the carb came with a short 3 inch stub line and a fitting,,I was told I could run a rubber fuel line to the outlet of the mechanical fuel pump about 25 inches away as long as I made sure the line does not rub or lay against a hot engine part,, do you think I would have a safety issue by doing this? thanks Dave”


NO, not as long as you use a rubber FUEL line. There are many rubber hoses you can buy, but you must use one made for carrying fuel (not vacuum pressure or oil or anything else.) Lines at auto parts stores are labelled so you can get the correct one. With a carburetor, your fuel inlet pressure is two or three pounds per square inch, so leakage won’t happen as long as you tighten the little stainless steel fuel clamps tightly. And on any fitting you have to screw in, put teflon tape on the threads BEFORE you screw the parts together. Then you won’t go down in flames from leaking gasoline.

Car waxing tips (is paste the best type wax)

John’s question:

Hey Scotty! Just finished waxing my car with paste. Man, was it tough and tiring to “wax off”. I had to use many towels to remove all of it. Is paste the best type of wax or is there something else better? Any tips or alternative to make the wax come off with out using massive amount of towels?”


Not if you want to do it right, it just takes a lot of work. Nothing beats the paste wax, it lasts longest. If you don’t like the tough rubbing, do just a quarter of a car at a time. I just did my old twenty eight year old work Toyota last week and I took three days to do the whole job by doing only part at a time. That way I didn’t go insane and sweat like mad in the already insane hot humid Texas summer. And of course, ALWAYS wax a car in the cool shade, don’t try it in the sun or you will be rubbing like mad. Yea, it’s a lot of work, but at least you know it’s been done correctly when you do it yourself. And realistically, you only need to do it four times a year, once a season.

Car window get stuck half way

John’s question:

My friends car window get stuck half way when try to pull it up. i noticed the window is misaligned and maybe the motor is bad. Knowing that it would probably be really expensive for a new motor, I sprayed PB50 lubricant on the edge. works fine now. Question: What is the “correct” type of lube to use because its rubber?”


The correct type of lube to use on windows and ANY rubber parts is spray silicone lube. You can get it at any auto parts store or hardware store. Just spray a bunch on, and wipe off the residue, it doesn’t make a mess at all as it wipes off easily (just don’t do it in bright sunlight as paint can be damaged if the car is really hot when you spray it on.)

ac controller and the windshield wipers don’t turn on at all

Karla’s question:

” The ac controller and the windshield wipers don’t turn on at all.What should I do?”


Well, then you should just drive where it isn’t hot, and doesn’t rain (I couldn’t resist that one.) To fix it, first check out the fuse box to see if you have any blown fuses, it could be that simple. But, if it’s not a blown fuse, then odds are you have two different problems. If that’s the case, wiper motor assemblies generally are the part that breaks in most cars. And if you have a GM vehicle (you didn’t mention what kind you have), the AC controllers themselves go bad ALL the time in them and need replacing.

Tricks To Pass Emission Test

Willard’s question:

My 97 Explorer is driving me nuts. It won’t pass the emissions test because it has codes for bank one and bank two running lean. The stupid thing runs fine, but keeps tripping these codes. What can I do?”


Well, quite a few things can cause those two lean codes to pop up. BUT, since you mentioned it’s running perfectly fine, then odds are you have an intake manifold gasket VERY small leak. Other problems that trip that code will generally make the truck run bad. Small vacuum leaks in the intake manifold will often not effect the running in any way you’ll notice. It is a pretty expensive job replacing the intake manifold gaskets, so you might try an old trick first (as long as it runs fine otherwise.) Have the computer reset with a scan tool, then drive on the highway going sixty mph for about thirty miles so the computer system will get itself ready and be able to pass the emissions test. (If you don’t drive it far after resetting the computer, you will fail the test because it will say that there are too many MILS not ready in the vehicle.) Then, if the check engine light doesn’t come back on, quick go and get it inspected. If the leaks are really small, the check engine light may not come on for a while, giving you enough time to get it inspected.

Spring/ strut replacement tips

Paul’s question:

Another question about the struts on the 1993 Pontiac Sunbird. Never worked on struts before… is it smarter(easier)to replace the spring/strut as a unit, or replace just the strut(car does bottom out pulling into driveway)? How hard to take them apart? Will I need special tools? And finally, do I need to purchase new bearing plates and/or strut cushion/mounts (if I just replace the struts), or do the new ones units come with new bearing plates? Thanks for all of your GREAT advice!!! Paul”


Basically, you should just replace what’s worn out. If the bearings are broken or their rubber mounting torn, replace them. If not, use them over. And there’s no sense replacing the springs if they aren’t cracked. Most stores don’t sell the entire unit with springs anyway, and those that do generally charge a small fortune for each one. You can either rent a spring compressor tool to do the job, OR, if stores like Auto Zone do the same in Buffalo as they do here in Houston, they will loan you the tool if you buy the strut replacements from them (not a bad deal.) With a spring compressor, it’s a pretty easy job.