I wonder if anyone might happen to know if the ECM in my car, a 2004 Terracan with the 2.5 litre turbo diesel, actually has any control of the diesel injection? Does the ECM act similarly in the 2.5 and the 2.9 engines?
Yesterday while on the highway, something quite strange took place. I have felt for quite some time that the power in my engine is very weak. While on our way to San José, early in our trip, after descending a hill, we began to climb up a hill, when suddenly, as if something in the fuel system had come unplugged, the engine began to pull very hard, enough to actually set me back in my seat. There are lots of places on this highway where the terrain in up and down, so lots of opportunity to see if the engine will continue acting the same way, and it seems that it has. The car began acting like a sports car, lots of power in the hills and an ability to pass just about anything.
I have been wondering if something that was holding the computer back from giving the enging full power, suddenly corrected itself or if perhaps the timing belt suddenly slipped a tooth and retarded the cam timing or ??? I would imagine that if the timing belt were to slip one tooth, it would slip a lot more teeth and calf the engine.
The sound from the engine now is different too. There is a lot more of the distictive diesel rattle while idling and under power.

There is more to this story........ a while ago I began experimenting with a hydrogen generator, creating hydrogen gas in a generator system under the hood of the car and injecting the gas straight into the air intake of the engine. In the beginning the gas changed the sound of the engine making it quieter and more powerful. However, the system that I built soon developed leaks and the engine was not getting very much gas. I need to design and build a much more secure system. About three weeks ago, I quit using the generator and the engine has continued being very quiet at idle and under power, until yesterday when this other condition took place. I do not think that my engine has sensors that would detect the presence of hydrogen gas in the exhaust system and consequently, cut back on the amount of diesel going to the injectors, or increase it and change the way the engine runs, but I don't know if it does or not. Anybody have any ideas about the association between the ECM and the pump?
Thanks to Robert for the info about the brake light switch, I'll check mine. Jeff Macleod, in Costa Rica. Cheers.

You do not state if your terracan has auto or manual transmission. Anyway, the service manual clearly shows a lot of sensors that go in the engine (injection pump and a lot of places) that do interact with the ECM unit.

The behavior you describe indeed seems that something was not working right and it fixed itself all of a sudden. That is strange. I can suspect many conditions for this to happen like:

a) There was an obstruction in the fuel lines that got cleared (including injector lines and/or injector nozzles).

(IMG:style_emoticons/default/cool.gif) There was something that didn't let the turbo kick in and now its working.

c) If you have auto transmission, then something in the transmission is throwing lower gears (more power) now. Probalby a stuck selenoid valve that got cleared.

d) Air intake filter was dirty and clogged and all of a sudden, something ripped a hole in the filter element.

e) You got a broken or loose exhaust pipe (rust for example). That would also explain louder engine noise when idling.

f) Wastegate was stuck opened (no turbo power) and all of a sudden began working correctly (turbo kicks in at 1500 rpm aprox)

In the meantime, I would have the Terracan be checked by someone knowledgable to rule out something bigger happening here that may lead to some kind of breakdown.

Robert B.

Hi Robert,
Thanks for your input. Five speed manual, air filter is good, fairly new, I don't know about the waste gate. The turbo does sound just a little bit louder, I can hear it spinning now more than before. The exhaust system is good, no broken parts or rust etc. The sound I'm referring to is the normal rattle that you hear in a diesel engine, the combustion process that has a distinctive rattling sound. Now, it is much louder. Before yesterday, the rattling sound was there, but very subdued, barely noticeable. Now it is quite loud. I know an injection shop here in Sarchi that might be able to offer some insight, I'll drop by there, maybe tomorrow and see what they have to say.

Jeff M.

I see. I will still have someone knowledgable look at it.

Some years ago I had a Galloper (same engine as yours) which did not passed RITEVE (smoke). I was recommended a diesel shop in Tibás who fixed my galloper (injector nozzle replacement, injection pump tuned and injection timing adjusted). They did a fine job for about half of what the dealer was charging. They are INTERPLAZA, located on the road that goes from downtown San José to Tibás, a few blocks before tibás shopping center, there is a gas station. The shop is across the the street (north side) of that gas station.

Robert B.

to Robert B., and others interested...
Thanks Robert for taking an interest in my situation and offering advice.
I took my car to a diesel injection shop today for their opinion and found the owner to be ready and willing to try to analyze my engine's characteristics. I related my story to him about having a louder fuel knock and more power. The owner took the crankcase ventilation hose from the air intake pipe and found there to be more than the usual amount of blowby coming from it. In the time that I have owned this car, the engine has never used any oil between changes. After seeing the blowby from the vent hose, we shut the engine off and waited a few minutes, then checked the oil, it was down a bit....not usual for this motor. Edgar is guessing that the engine has broken some piston rings and the resultant blowby means that the engine is burning the oil fumes from the crankcase and from that, producing more power. Tomorrow my local mechanic is going to pull the injectors and do a compression test. That should give us some more info to analyze.

Now this brings more questions to mind...
Does this engine have wet liners? If so, would it be possible, if this engine needs rebuilding, to replace my liners and pistons with liners and pistons from a 2.9 litre engine? Are the 2.5 and 2.9 engines built using the same block? Are there other Hyundai four cylinder diesel engines of different displacements using the same block? If it may be possible to increase the displacement of this engine somewhat and fit it with a larger turbo, it might actually end up with enough power to make it a more desireable car to drive.

Jeff M.

The thot plickens, (Canadian humour)

My Terracan is in the shop. The mechanic has the engine torn down to the point where he was trying to get the oil pan off this afternoon. The head is off, which means the timing belt cover is off, which means that we can see that the timing belt is a bit loose and we can see that the intake valve in #4 has been touching the piston. Also very evident is that there is a second timing belt in this engine.....a timing belt for a counter balance shaft, which runs longitudenely from front to back in the driver's side of the engine. This timing belt was broken. This could be the reason for the sudden surge in power... the engine suddenly not needing to turn this shaft, so more power is available to the wheels.
The mechanic told me that the head has been off this engine before and that it had been planed, but not very well. It needs to be planed again. When I bought this car, in November of 2007, the speedometer showed 59000 kms. It now shows 79000 kms. My mechanic says he thinks the engine has approximately 125000 or more MILES. He showed me that the pistons are loose enough in the cylinders to warrant changing the rings. He also says that the injector tips need changing. The more I see, the more I'm thinking that this car was misrepresented, a sad but true part of life on this planet.
Tomorrow the pistons should be out and we will be able to see the rings and bearings. There is no ridge at the tops of the cylinders and therefore, maybe, the block will not need a rebore.
At least the timing belt did not break and destroy the important parts.

Cheers, Jeff M.

Well my friend, its bad to see you had to take apart the engine for a full repair. Its also bad to discover the engine head was previously worked on (not good as you say), but anyway, at least you have the car with someone who seems to know what they are doing.

Good thing about this engine, is that the 2.5 lit turbo is so widely used by Hyundai (Gallopers, terracans, Starex and even older models of minibus H100) that parts are widely available from many aftermarket suppliers. This also means that the engine is widely known by many good mechanics around.

May I remind you that I have the service manuals for that engine (whole service manuals for terracan) in case you need them. We can arrange something so I can pass you this manuals in a CD.

Robert B.

Robert B.,

Thanks for your offer, that's very kind of you. I will let you know how things go and if I need the manuals.

Regards,
Jeff M.

It's been a while since I contributed to this column, so I thought I would add some info to bring those interested up to date.

My car was in the shop for a month, and I was in Canada for another month, with my wife and the youngest daughter, so some time has passed by.

It turns out that the engine in our Terracan had to come out and be completely rebuilt. The block had to go to a machine shop to be bored slightly to true up the cylinders. The newest pistons were stamped "STD" but could be slightly bigger than the originals to fit the refurbished cylinders. The cylinders were about 6 thousandths of an inch out of round, so the block went out to correct this condition.
The head went out to be planed to true it up, new valve seats were installed. There are now new pistons and rings, new bearings, a new kit put in the turbo, new timing belts, new injector tips. The injector pump went to an injector shop where the mechanic reported that the pump was like new. It looked as though he replaced some seals and washers and sent it back. The oil and water pumps were both replaced. One engine support mount had to be replaced as did the pilot bearing and the clutch release bearing. Just about everything except the crank and connecting rods are new and the engine runs quietly and smoothly. I reported in one of my other posts that the engine had a balance shaft in it, but it turns out that there are two shafts, one at the top, left side of the engine and the other at the bottom right side. These contribute to a very smooth feel to the engine as it is running. I believe that it is possible that the head had to be planed because the former owner was not aware that turbo charged engines require a short idle time at the end of a driving experience, to cool the turbo down and to cool the head, before shutting the engine off. I am aware that this habit may be somewhat inconvenient for some drivers, but if followed, will mean many more trouble-free miles from the engine. It only takes a minute or two to cool things down after the engine has been working hard and is smokin' hot.

All the best, Jeff M.

Well, it seems your engine needed a good rebuild. I guess it didn't come cheap and a fair amount of money was put into it. Anyway, now you know you have a new engine.

Is it running now or there are some other issues to correct?

You are right about some people ignoring turbo engines need some idle time before shutting down. The turbo itself is the one that suffers great damage by not doing so, because if engine us stopped right after a fast run, then the turbo keeps spinning without oil pressure. The head too will suffer but not significantly.

Robert B

Hi Robert, thanks for your reply,

I think that should be it for a while. There was a high pressure oil hose from the right side of the engine, leading to the oil cooler in front, that began to weep through the braiding, probably due to the new oil pump having more oil pressure. We replaced it and now everything seems to be right. There is still a rattle somewhere near the gearshift, that I thought might have been from the bad condition of the pilot bearing in the center of the flywheel, but that bearing is new now, and the rattle is still there. I can't see anything from under the car that is loose, so I'll just have to keep looking.
After our first long ride, to Bijagua, near Upala, last week, we managed 24.9 miles per imperial gallon. Hopefully that will improve as the engine breaks in.

Cheers, Jeff M.