This page is about the 2001 VW Golf TDI that runs on 100% pure vegetable oil.
Few people know that most modern diesel vehicles can run on fuel made from vegetable cooking oil. In fact, the original diesel engine was designed to run on peanut oil! Many years ago I learned about using waste vegetable cooking oil to run vehicles and over time have become very interested in running a straight vegetable oil (SVO) vehicle. In March of 2009 the quest for a usable diesel vehicle came to an end when I found a online classified for a 2001 Volkswagen Golf TDI. This page is a record of the 2001 Golf and using waste vegetable oil as fuel.
For a background in SVO and biodiesel, check out the biofuels page here at The Smart Drive.
The Vehicle
In March 2009 I was browsing classified pages and stumbled across a listing for a 2001 VW Golf TDI with SVO kit installed. The owner of the Golf was a sustainable fuel fan and had been running SVO for over 40,000 miles “without a hitch”. A Carfax report showed no issues and the owner stated that the vehicle had been well maintained over its life. One would wonder why an SVO fan would sell an 01 TDI? Well, over time the vehicle started to loose power and compression in one of the engine cylinders. After removing the head of the engine the owner noticed scoring on the wall of a few of the cylinders, which he had assumed to been caused by particulate from a detached air filter. A few months after finding the scoring the owner decided to sell the vehicle with the damaged engine…enter me! Two days after finding the listing I was the proud owner! To get the car in running shape the cylinders would have to be bored oversize, which means removing the engine. Since I lack an autoshop and engine tools I got quotes from a local VW shop and an engine shop to do the repairs. Even after the repairs to the engine the estimated cost would be well below blue book value for an ‘01.
Engine repairs
After some investigation of shops in the area I settled on a local VW specialist and a local shop that rebuilds engines. About a week after the purchase the vehicle was towed to the VW shop where they removed the engine. Now, when the engine got to the repair shop, that’s when things get interesting and (of all things) educational!
The owner who sold me the vehicle said that the scoring was only on cylinder #1 and caused by a detached air filter. This caused dirt and other particulate to enter the engine and over a few thousand miles caused the damage. Well, I stopped into the shop the day the short block was dropped off and the owner took one look at it and said the scoring was caused by heat….strange.
A few days into the engine repairs I visited the shop to see how everything was going. When I walked in I was greeted with “Your engine fell apart” from the owner. I must have had a priceless look on my face because the owner just laughed and said “It’s fine, we just had a hell of a time getting the pistons out”. The owner of the shop explained to me all four cylinders were scored and there was a lot of carbon build up on the pistons and piston rings. He also asked if the previous owner had run vegetable oil!
Here is where it starts to get educational. Vegetable oil has a higher viscosity than petrodiesel, thus, to burn it in a diesel engine the oil’s viscosity must be lowered. The easiest way to lower the viscosity of WVO is heat it up. Many people with WVO kits use excess heat from the engine and/or in-line fuel heaters to do this. If vegetable oil is used as a fuel without being heated it burns incompletely. This incomplete combustion results in smoke from the tailpipe, low power and deposits of carbon (or soot) on parts of the engine. As one would suspect, poorly filtered oil can also clog fuel injectors and cause carbon buildups. Many people hang filter bags and gravity filter their oil, be careful unsupported filter bags stretch under gravity
.
Carbon build up sounds like the symptoms the former owner of the car was experiencing. After some research what it seems happened is the injectors became clogged/worn and failed to spray an adequate fuel pattern, causing carbon build up. These deposits caused the oil ring of the pistons to clog and the friction between the rings and cylinder caused the cylinder wall damage. For more information on what can clog injector nozzles, check out the “Volkswage TDIs and Vegetable Oil” section below.
Here is a video of the pistons and engine block with scored cylinders.
To get the engine back in a running state the cylinders must be bored out by 0.5mm and new pistons put in to fit the new size. When rebuilding an engine you also have to replace things like gaskets and bolts. Now since the car has 100,000 miles and the engine is out of the car, it makes sense to replace the clutch and oil pump, so that’s what I did. After all is said and done, this car will have a damn near new engine with almost zero miles on it. For a breakdown of what was replaced check out the “Cost Breakdown” section below.
Volkswagen TDIs and Vegetable Oil
As I mentioned in the section about engine damage, under-heated or poorly filtered oil are two causes for carbon deposits and engine damage when running vegetable oil. While these are important to avoid I have found a lot of information online about the problems inherent with of running SVO/WVO in VW TDI engines. See ” The TDI SVO Controversy“, this TDI Club thread, or this thread about a melted piston. It seems that many people have reported carbon build up just from running vegetable oil.
For now, some long hard thought is going to have to go into this issue and how to prevent replacing my injector nozzles every few years.
It should be noted when I mention TDI, I am talking about the VE type TDI from VW, not the newer style PD TDI produced from ~2005 on.
Cost Breakdown
In the interest of those looking to fix up a TDI here is the cost breakdown for The Smart Drive 2001 Golf:
TDI Parts
| 2001 TDI Golf with engine damage | $2,700 |
| Oversize Pistons | $470 |
| VR6 Clutch | $330 |
| Oil pump | $130 |
| Rod Bolts | $40 |
| Injector Nozzles (4) | $300 |
| Gaskets and sealer | $65 |
| Glow Plugs | $80 |
| Head Gasket | $40 |
| Shipping | $20 |
| Total | $4,175 |
TDI Labor
| VW Shop (Estimate) | $2,500 |
| Engine Shop (Estimate) | $1,500 |
| Injector rebuilding (Estimate) | $100 |
| Total | $4,100 |
Vehicle Total
| Parts | $4,175 |
| Labor | $4,100 |
| Total | $8,275 |
Asset Breakdown
| 2001 TDI Golf cost | $8,275 |
| Replacement of gas car | -$2,000 |
| Blue Book value of 2001 Golf (5/6/09) | $8,125 |
| Market value of Greasecar kit in vehicle | $900 |
| Net Vehicle Replacement Cost | $6,275 |
| Net Vehicle Value | $9,025 |
| Net Asset Increase | $2,750 |
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This is the status of the car as of April 20, 2009. Check back for updates soon!
View all the SVO project post here: http://thesmartdrive.com/category/project/svo-car/