A heavy oil used in compression-ignition engines.

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45
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8answers
6k views

What to check when buying a used car?

I'm looking to buy a used car. What do you think I should check (mechanically) before buying it (especially if it's diesel)?
35
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6answers
6k views

Why do heavy vehicles almost always use diesel engines?

I have always wondered why heavy vehicles such as large trucks and buses almost always use diesel engines, whereas in light cars there is a choice between diesel and gasoline engines. Engine ...
16
votes
5answers
3k views

Why not use gasoline on diesel engines or vice versa?

I've read gasoline engines use sparks to ignite the mixture, but diesel engines use just compression which can't be done in gasoline engines due to high compression ratios which can cause engine ...
12
votes
9answers
11k views

Diesel vs Petrol motorcars. Pro's and cons?

I realize this may be a silly question to those of you on here who are proper petrol-heads and this may even be a repeat question, but I could not find anything on it on here, so here goes: What are ...
12
votes
5answers
29k views

How to test for defective glow plugs?

On a diesel engine, how can I know which glow plugs are defective, and can I change these only?
10
votes
2answers
190 views

Diesel Engine Runaway - What is it?

I was watching some youtube videos and diesel engine runaway videos started to pop up where apparently the diesel engine runs out of control until it destroys itself. My Question What is diesel ...
10
votes
1answer
92 views

Why do diesel fuel lines have to be bled?

Background I've had a couple of situations with diesels. One in particular where I swapped a Ford F350 Powerstroke 7.8 transmission. When I was done. The truck wouldn't start. It was a painful ...
8
votes
5answers
22k views

Is it normal for the oil to be dark in color right after an “oil change” in a 10-year old diesel car?

I took my 2002 Jetta TDI wagon to a neighborhood shop about 10 miles, 24 hours ago. They supposedly changed the oil, but the color is very dark, almost black. Definitely not light-colored/transparent. ...
8
votes
2answers
2k views

Modern cars and diesel warm-up time

First of all let me say that I already read this question and its answer, so it's clear to me why diesel-powered cars need a warm-up time. My question is: do modern cars need it too? I have VW Golf ...
7
votes
2answers
427 views

Two-Stroke Diesel Engine - Do they use forced induction on them?

As I have indicated before, I'm very diesel ignorant. I just know the basics, very basics. In a two-stroke diesel engine using forced induction seems necessary but at the same time I see challenges. ...
7
votes
2answers
7k views

Why do head gaskets fail in diesel engines?

I'm considering the purchase of a 2001 VW Golf TDI "mechanic's special", so named because it apparently has a failed head gasket (white smoke). I'm not a mechanic but I'm fairly handy with tools and ...
7
votes
2answers
399 views

Why does a petrol engine need to maintain an air-fuel ratio, while a diesel engine doesn't?

This simple question has been bugging me for a while. The amount of fuel injected into a petrol engine is calculated according to the amount of air entering through the throttle valve (as measured by ...
7
votes
3answers
170 views

Why don't all diesel engines have throttle plates?

I learned recently that many older and some newer diesels don't have throttle plates to control airflow. I was also quite shocked to learn about a condition called diesel engine runaway. Apparently ...
7
votes
4answers
102 views

2002 Ford F350 Superduty 7.3L Turbo diesel using a quart of oil every 43 miles

This Diesel engine has been rebuilt and it didn't use any oil till the HPOP went out. I replaced the oil pump and then I noticed my turbo when going up a hill and the Turbo would sound like a sneeze ...
7
votes
2answers
253 views

'83 Mercedes 300D will not start when warm

The car runs great when first started, great pickup, etc. However, if I stop and shut off the engine, it will not start back up. At times I can pump the accelerator 5 or 6 times and then it will start ...
7
votes
1answer
305 views

Intermittent starting trouble with new battery

I sometimes have problems starting my 2003 Ford Fiesta Diesel. When I turn the key it'll either start normally or just start to kick over then die. If I try again, the same thing happens. My battery ...
7
votes
2answers
45 views

Proper glow plug operation

Are glow plugs supposed to stay on after the engine has started to help with the firing of the first few revolutions?
7
votes
0answers
41 views

Ford Tractor 5600

This is a older tractor. My question relates to the fuel system. The older fuel injectors don't have any external seals? All of them seat and 3 don't leak but one does. I was looking for a seal but ...
6
votes
3answers
2k views

Why are VW recalling their cars to remove a defeat device?

As I understand it, Volkswagen had software to artificially enhance their efficiency ratings on a test rig. Since it would only be active under test, what is the point of recalling millions of cars to ...
6
votes
3answers
2k views

What kind of engine oil should one use in a diesel?

I got an 1987 Toyota Land Cruiser with a 2H diesel engine. I never changed oil on a diesel engine prior to this truck, so I'm a little confused. Toyota Factory Shop Manual recommend API CC oil type, ...
6
votes
1answer
82 views

How are diesel engines better for the environment than gasoline?

I understand that diesel engines have become much more efficient at controlling emissions over the last couple decades. Various websites like this one describe the technological improvements that have ...
6
votes
6answers
5k views

what can be the reason my old diesel Mercedes won't start?

The vehicle is a Mercedes-Benz T1 model 308D. The engine is an old Mercedes-Benz OM601.940 4-cylinder indirect injection 58 kW (79 hp) 2299 dm3 diesel engine from year 1992. It's not a turbodiesel! - ...
6
votes
1answer
109 views

Car can't start after rocker gasket change

I have a 2008 BMW 120d LCI with N47 engine. Recently was diagnosed with some oil leak on the rocker gasket near the injector area. Were advised to change the rocker gasket seals. So I did change the ...
6
votes
1answer
78 views

Two-Stroke vs. Four-Stroke Diesel Engines - What is most commonly used in heavy vehicles?

I am not well versed in diesel engines. To prove my point, I've learned in the last month that a two-stroke diesel engine actually exists. My Question. What kind of diesel engine (four-stroke or ...
6
votes
1answer
93 views

Can diesel engine be harmed as easily as gasoline engine by over-revving?

There is an excellent Q&A about why diesel engines have lower redline RPMs (about 4500 RPM) than gasoline engines (about 6500 RPM). The reason is related to the combustion of diesel fuel. ...
6
votes
2answers
792 views

Diesel engine starting / first start of the day problems

I’m new to the forum, and no mechanic, so please be kind! Vehicle in question is a 1999 T35 Renault Master 2.5 D. It has had first start issues since I’ve owned it, with white smoke (un-burnt fuel ...
6
votes
1answer
4k views

Re-programming injection pump on French Ford Focus TDCi

I replaced the engine on my 2003 Ford Focus (French TDCi) and I plugged it to clear the error codes. Now it starts ok but stops after 10 minutes. I read that when a new injection pump is installed, ...
6
votes
1answer
89 views

Volvo S80 II 2.4 D5 DPF (Diesel Particulate Filter) regeneration conditions

What are the conditions required for the DPF (Diesel Particulate Filter) regeneration? Is it only exhaust temperature or speed and RPM also? I'm wondering if DPF can regenerate while car is at ...
6
votes
2answers
3k views

BMW 530xd e60 2008 diesel engine turns but won't start

I have a problem with my BMW, just bought it, previous owner hasn't been facing such problems. When the engine is cold for e.g.: after night. Outside temperature is about -4 to +1 degree, engine won't ...
5
votes
2answers
3k views

Why does diesel engine have redline much lower than petrol engine redline?

why do diesel cars redline at around 4500 rpm whereas petrol ones around 6500 -8000 rpm? Does this have something to do with the compression ratio?
5
votes
2answers
621 views

Petrol vehicles, what are the advantages and disadvantages of a turbo charger?

Diesel vehicle often use turbo chargers. Petrol vehicles frequently do not. What are the advantages and disadvantages of using a turbo charger on a petrol engine?
5
votes
2answers
182 views

Would a non-turbo diesel perform better in high altitudes than a comparable gasoline engine?

I live close to the Rocky Mountains and drive into them quite often. I have a small naturally-aspirated four-banger that tends to lose a very noticeable amount of power getting into the higher ...
5
votes
2answers
2k views

BMW 330D 2001 E46 Turbo Charger not working as expected after changing

I have a problem with my car. My car: BMW 330D, 135kw, 2001 year, E46. A week ago my turbo charger got broken when I was driving. There was a lot of white smoke going out of exhaust and there was ...
5
votes
1answer
50 views

What is DEF and how is it used?

I keep hearing about DEF ... what is it and why is it used in conjunction with diesel engines? I know it is a more recent thing (last decade), but don't know much about it.
5
votes
2answers
542 views

What does this device on a 1985 Mercury Lynx/Ford Export Diesel do?

I have a 1985 Mercury Lynx (Ford Escort) Diesel 4 cylinder. The device shown in the pictures -- below the starter -- has a hose connecting it to the radiator. There is another hose that is ...
5
votes
1answer
151 views

Possible EGR problem on Fiat Idea Multijet 1.3 Diesel

I've been having issues with my 56 plate Fiat Idea for a while now. It seems to drive normally up to about 2500-3000 rpm where the car lurches a little, as though i shifted down a gear, the MIL light ...
5
votes
1answer
68 views

Ford Focus engine cuts out at 3000+ RPM

I should provide a little background to this issue as I believe the two are most likely related. The car is a Ford Focus 2008 1.6 TDCi Diesel (UK) which this year has had a brand new battery and ...
5
votes
2answers
29 views

Hyundai i30, 1600 cc Difficulty starting

Hyundai i30 model 1600 cc Auto. diesel, now done 60,000 miles. About 10 months ago, I had difficulty starting the engine from cold. The temperature would have been in the 50 to 60 degree Fahrenheit ...
5
votes
0answers
32 views

How will diesel engine perform with air in fuel line?

I recently replaced a fuel filter in my 2005 Dodge Ram 3500 Cummings (5.9L). I'm now getting performance issues: at low speed, and especially starting from a stopped position, I'm getting low power. ...
5
votes
0answers
45 views

Mahindra KUV 100 and Suzuki Alto OBD protocol

Can someone please tell me the OBD-ii protocol of Mahindra KUV 100 (diesel) and Suzuki Alto (diesel). Also whether ELM 327 Bluetooth will work? ...
5
votes
0answers
40 views

Why is there no drop-in biogasoline like there is drop-in biodiesel (e.g. NEXBTL)?

I have always wondered why there is no drop-in biogasoline like there is drop-in biodiesel. For example, NEXBTL by Neste can be run at 100% mixture in conventional diesel engines. It is different from ...
5
votes
0answers
54 views

1983 Mercedes Diesel - Loses Power Over Time

I picked up this car as a gift, and on day one drove it the 370+ miles home. After the first 160 miles or so I noticed that the car was struggling to maintain highway speeds. So I pulled over into a ...
4
votes
3answers
1k views

How to diagnose ABS problem (ABS light on) on a 1992 Volvo 940 turbo diesel estate?

The ABS light came on after car was not used for a few weeks and a new battery fitted. The ABS light is now on all the time. The garage can't find the diagnostic plug. Any ideas on either of the ...
4
votes
1answer
76 views

How much to get an old restomod running?

potentially a difficult question here. It's looking like I'm going to be moving out of state for a new job here in the next few months, which is throwing a big wrench into projects I have going on. ...
4
votes
2answers
263 views

Can I use a CNC machine or waterjet to make an adapter plate to adapt a 5 speed transmission to a rare, obsolete engine?

I am the sad, proud owner of a Nissan SD33T (Diesel), mated to a 4 speed T-19. The power this engine outputs (101HP, 160#/TQ stock) means it struggles on the highway, and I don't want to sacrifice my ...
4
votes
1answer
3k views

2000 VW Golf TDi (Mk. 4) grey smoke from exhaust before engine has warmed up

I have had my Golf for 8 years. It’s had good maintenance and a the record is kept by my dad. It’s just passed its MOT (Ministry of Transportation) test, and the mechanic mentioned that the tappets ...
4
votes
1answer
107 views

Octane rating of fats and oils versus diesel fuel

I'm struggling to understand why, apart from viscosity, it's so easy to substitute lipids (i.e. SVO, WVO) for diesel fuel. I'd have to assume these fuels have inherently different octane ratings and ...
4
votes
1answer
275 views

Accidently put biodiesel fuel in 2009 Nissan Altima. What to do?

I made a really stupid mistake earlier tonight. I was at a gas station refueling my 2009 Nissan Altima (2.5L 4-cylinder engine). I stupidly selected the only option that was available at the pump ...
4
votes
1answer
552 views

Biodiesel and DPF (Diesel Particulate Filter)

I read a little about DPFs and biodiesel. Some claim that there's a reduction in lubricity and/or viscosity of engine oil when using B30 or above. They warn about increased engine wear because of it. ...
4
votes
1answer
22 views

Coolant type for 1977 Diesel

I have a marine 1977 Perkins T6.354 6 cyl, 6 liter turbo diesel. There are different types of coolant available and I've done significant research into this question and have not found a clear ...