[Mike SX]

You probably are; fault finding is a difficult science - you usually look for one problem, but when there are more, confusion shoots in, as issues become clouded.
Failure to start was corrected (after several visits) about 6 months before LHM started.
Was your c/c factory fitted or after market (Dancar Hyundai Approved Accessory) ? An obvious difference is that mine does not require the brake pedal actuated for the c/c to engage; factory fitted does - safety reasons.
Car ran perfectly for several months, until c/c loom voltage fluctuations on the CanBus caused problems - seems most manufacturers use gold plated contacts, whereas the faulty loom did not.

Update August 2014 -  the fourth brake switch has been replaced, and the c/c does now require initial foot brake operation, minimum activation speed, and other operational changes. The fuel consumption has decreased & 63mpg (measured by brimming) was achieved by a recent 1200 mile round motorway trip, all roads driven at the maximum permissible speed

[Foglefar]

Ours is a factory fitted CC.

[sundiz]

I've had a used i30 for a year and now it joined the limp mode club. This happened first time when the temperature dropped from 0*C to -10*C in one night. Limp mode came back every time the revs went up to 3000-4000. I was able to get the car in to the limp mode and connected OBD2 reader to the car. I got the code P0087 (low fuel rail pressure). The code was not saved in to the memory. It was some sort of "present" fault code. But it was not saved in the memory. Also there were no "check engine light" (or any other warning light), only the limp mode. Next time when I started the car I was not able to get any fault codes.

This happened couple of times. I thought that fuel filter might be dirty, so I changed it. Seemed to work for a while. I drove about 1000km and the car went back to limp mode. This time I got the code P1186 (low fuel pressure). I looked possible causes from GDS. It says in there that possible causes are for P1186: rail pressure sensor, rail pressure valve or fuel pressure valve. GDS had the same possible causes for P0087 also. Cause I don't have the multiplexer between PC and car, I had to take the car today to Hyundai service. It will sit there one day before they have time to check the system. They will check the possible fault codes from the car with GDS. I checked the resistance of the rail pressure valve with a multimeter and it seemed to be OK ( around 3.7 Ohms). But all I can do now is to wait and see if the Hyundai mechanics can get some actual data from the fuel sensors.

My car is manual with no cuise control...

[Asterix]

Hi

Will be interesting to hear Hyundai's findings.

Just a thought. As you say it helped to change the fuel filter, could the fault be a small leak somewhere to allow air into the fuellines...

If air enters the rail it maybe wouldn't be possible to build up the required pressure..

[Phil №❶]

I wonder whether you have a fuel problem. In your country I assume winter Diesel is on offer all the time. It can turn to a thick substance if the summer fuel gets too cold. There is also supposed to be a fuel heater near the filter, but not much use if the fuel can't get to the heater from the fuel tank.

Keep us posted. 

[Dazzler]

 

 

[sundiz]

This is my first diesel, so I haven't got so much experience of diesel car problems. Used to drive old merc for a long time so these new modern cars are way out of my expertise.

We have different diesels for different seasons. In summer they sell summer diesel, in winter they sell winter (or even arctic diesel). I had this diesel in the tank which should work in -10*c. Of course there will be problems if there is any moisture in the fuel system with those temperatures. Moisture in the fuel system and cold itemperatures are a common problem here with diesel cars. Therefore I changed the filter. Last time when the car went to limp mode I had a full tank of winter diesel.. That works in -25*C temperatures and it was only +4*C so the temperature should not be the problem.

A leak was also in my mind. I looked all the fuel lines under the hood and they seemed to be dry (from the outside). So atleast no diesel was coming out of any high pressure system. Or then I just did not see it. If there were an air leak, shouldn't it be somewhere before the high pressure pump? Cause the pressure is so high in common rail, in my opinion the fuel should come out, not the air go in. But if there were a bad seal or connector before the high pressure pump I guess that pump could create a vacuum in the fuel lines which would suck air in. But I quess anything is possible with these modern day magic motors. My best quess based on the measurements I made and the data from GDS that the problem is the rail pressure sensor or the fuel pressure valve. But I will let you know the results, what ever they are. Hopefully this will help some other unlucky i30 owner with similar problems.

[Phil №❶]

Sorry to hear you're having difficulties, they really are very good cars normally. Moderator Asterix in your climate, tows his van every year in Europe and has testified here how good the car is, his car has a few kms on board, too.

[Mike SX]

Thanks for your input, any information is greatly appreciated as it helps others in a similar situation (knowing they are not alone as well....).
Every little bit helps 

[sundiz]

I must say I got pretty good service from the local Hyundai dealer. Never got this fast service with my old merc. They were supposed to check the car tomorrow at noon, but they called today at 9 am that the car is ready to be picked up. Unfortunately they were not able to get the car in limp mode. They drove 30km with analyser connected to the car, but nothing happened. Car worked fine.

Based on the information I gave about the fault codes P0087 and P1186 they ran some tests to the fuel pressure sensors and pressure valves. Everything worked as intended. They were not able to find a real cause for the limp modes.

One mechanic had told to service manager that there had been one car with similar problems some time ago. Random limp mode and no fault codes... They were able to fix the problem with new fuel filter. They did not change it to my car because I had changed it myself just over a week ago. They told that I might have fixed the problem with new filter and the last limp mode was just some sort of odd bug in the system. But difficult to say what was the real problem without any evidence. They recommended that I'll go and buy some fuel system cleaner and add that to the fuel tank. I asked if they could do that for me, and they did. Now I have Forte fuel system cleaner in the tank and we will see if that helps. Service manager told that with some brands like Skoda, Forte treatments are done as a part of normal service of the car and those treatments are recommended by the manufacturer (Skoda).

If the limp mode comes back, I might change the filter once more, if I can't get any other fault codes out of the car. I used genuine Huyndai part last time, because I red from somewhere that aftermarket filters have caused some issues in someones car. If there is some dirt in the tank that plugs the filter, changing the filter might help to clean up the system... or not. But I'll hope that the current filter and Forte treatment will help. Here, because of winter, it is  recommended in general that diesel fuel filters are changed every fall before temperatures go below 0*C.

The Forte treatment was 20€, checking the system and sensors was 100€. 120€ bill was not too bad. With merc service they usually charged that for just walking in to the shop 

[Phil №❶]

I hope it's fixed. If you're unlucky to have it occur again, record the temperature outside the car for reference. They may not have been able to reproduce the fault because the temp was warmer when they tested.

Not sure of your mechanical abilities, but if there is some dirt or foreign material in the tank, replacing the filter won't fix your problem. The best way is to fully drain & clean the tank and flush the fuel lines completely, otherwise you will just keep replacing filters until they block again and that is expensive and very inconvenient, long term.

[sundiz]

Well, today the temperature went below zero again. Car went in to the limp mode again. I guess this is going to be a long battle... I got the code P1186 again. I guess I have to wait until the temperatures drop and take the car to service again. Last winter the car worked fine...

[Asterix]

You said you had checked the resistance in the fuel pressure sensor.

Is it just a 2-pin connector..

What if you disconnect the sensor and connect the pin 1 & pin 2 so the ECU allways get the low resistance. Try driving with that for a period..

[sundiz]

You said you had checked the resistance in the fuel pressure sensor.

Is it just a 2-pin connector..

What if you disconnect the sensor and connect the pin 1 & pin 2 so the ECU allways get the low resistance. Try driving with that for a period..

I checked the resistance of rail pressure valve. That has only 2 pin connector and the resistance should be 3.42-3.78 Ohm according to GDS. That valve is on the left side of the common rail when you stand in front of the car and look under the hood.

The rail pressure sensor is on the right side of the common rail. The pressure sensor has 3-pins. The GDS says that the sensor should give under 1.7V when motor on idle (fuel pressure 220-320bar and approx 4.5V when full pressure in the common rail (1600bar). I just dont know what pins I should measure to check those values. I think it needs some sort of adapter if you want to measure those voltages when car is running and sensor is connected, because there is no contact where you could connect your multimeter when the sensor is connected to the wire. Seems like I have to spend tomorrow under the hood. There is also fuel pressure regulator valve in front of the motor that I could check. That should have resistance of 2.6-3.15Ohm.

Car worked fine when I came back home. I've started hoping that something would actually break down so it would be easier to fix. This random limp mode thing is really annoying.

[sundiz]

I spend some quality time with my car at the garage. I opened every sensor or valve plug I was able to see in the fuel line system and cleaned up the contacts with electronics cleaning spray and compressed air. I also re-measured the rail pressure valve. The valve is on the left side (black circle) and the rail pressure sensor on the right (yellow circle).



The pressure valve seemed to be ok.



One trick for people who are not into electronics: When measuring these really small resistances (couple of ohms) the wires of the multimeter affect to the reading. It shows now that the resistance is 4.2 Ohms. That is out of the specs (3.42-3.78 ohms). With my cheap multimeter the resistance is about 0.5 Ohms when the tips are connected together, nothing between them. So you need to count 4.2-0.5=3.7Ohms. That value is ok. With larger resistances the test wires don't play so big part and can be ignored.

The pics in the GDS aren't very good. I was looking for the fuel pressure valve and I am not sure if I found the right connector. I measured the resistance from this pin and I was around 3 Ohms. That would fall in the spec of the fuel pressure valve (2.6-3.15Ohms). I', just not sure if that was the right connector.



I also checked the fuel (pump?) fuse, that was ok. Then i moved some other fuses to make sure they get good contact. At last I was going to check the fuel (pump?) relay, but it was really stuck. I had to help it with screw driver just to get it moving. I was almost out and just before it would have come off the relay crumbled into my hands. No sure if it was crappy relay or am I just too strong, but the relay broke down. Lucky for me most of the relays are similar so I took the relay from the horn and used that to replace the fuel (pump?)relay.

I did a small test drive and the car worked fine. There was +1*C so the temp. might have helped. Guess I'll see what happens when it gets cold again.

I'll have to go buy couple of relays next week, because the car is not so horny anymore...

Oh man. I just remembered on thing when writing all this stuff about the "fixes" and temperatures. I got some freeze spray in the garage. I guess I could spray that to fuel valves and sensors to see if I could get the car back to limp mode. Maybe tomorrow...

[Phil №❶]

Just wait for the temp to drop naturally. You won't be able to simulate what's happening just with freeze spray as the "problem" may be in the fuel line from the tank to the engine. At least you've checked all you can for now.

Thanks for the pics & tips.

[sundiz]

Car worked fine couple of days. Today when I left work limp mode came back. Got the code P1186 again... I don't think the temperature has anything to do with the limp modes. It was +8*C today, so no frozen water in the system.

I've started to browse some kia forums also, because they might be little more popuiar cars and there are quite a lot of same parts in ceed and i30. I found some russian kia forum and it looks like someone was able to fix this kind of problem by cleaning the fuel pressure valve. Or at least it looked like that when I used google translate  Or what ever the thing is on the top of the high pressure pump. Looks like it's connected with 3 hexagon or torx bolts. Same valve/sensor than in the last pic I posted. Has anyone opened that sensor/valve? I would like to check that if its dirty, but I was just wondering if that can be done by "amateurs". Is there some high fuel pressure that is going to spray some diesel around the garage if I start opening those bolts. Or can that thing even be taken out without taking the highpressure pump out before?

[Lorian]

high pressure fuel pump itself faulty?

[sundiz]

high pressure fuel pump itself faulty?

That is possible. I saw one topic at some kia forum where a sorento suffered from identical problems. That was fixed by changing the high pressure pump. But I hope it is something else (cheaper). That pump probably costs a fortune + labour and my car is out of warranty. My car has "only" 76 000km and if high pressure fuel pump doesn't last longer than that I would be really disappointed to the quality of the Hyundai.

[Dazzler]

Check out these old threads .. There was a problem with some early FD's with the fuel sensor (might be fixable outside warranty if you are lucky) 

Hopefully you can access them via these links...

Smoking tires and accelation issues with my new i30cw 1.6 CRDI

Acceleration Problem in i30 1.6 Diesel

Labouring/lack of power

[Phil №❶]

That pressure sensor should NEVER get dirty as the fuel has been filtered prior to reaching that section of the car. BUT, thee is an inherent design fault in common rail Diesel's in that there is no further filtering after the initial fuel filter. This means that should any portion of the high pressure pump or other components fail, their bits could pass through the pump & injectors which would be the only way your sensor could get dirty.

Personally, I wouldn't touch it and as you seem to continually get an error, why not just replace the whole sensor. It could be inspected at disposal to see if any foreign material was causing the problem, too.

As far as the temperature, well we can now rule that one out.

[Dazzler]

, why not just replace the whole sensor.

Just a small matter of cost Phil... 

[Phil №❶]

O I C 

[sundiz]

Car worked OK today. I sent yesterday an email to other local dealer service experts and asked their opinion what should I do and do they have any other ideas. They said there have been some minor issues with the fuel filter assemblies: small leaks, small fracture in the heating element wich sucked air in etc. The filter assembly could be the problem, but there might be also many other possible causes. New filter assembly with new sensors would be the "cheapest" thing to replace. That whole assembly would cost around 270€. If the problem is in high pressure fuel pump or in the injectors, then it would cost a fortune to fix the problem...

It got a lot better when  changed the filter. In my opinion there was a small amount of water in the water separator when I removed the old filter. The temp did drop to -10*C the night before the first limp mode so if there were some water, that should have been frozen. In physical point of view, water expands when it freezes. Therefore the expanding ice might have damaged the filter and the filter assembly. Does this make sense to anyone else, or am I just making things up while trying to figure what the hell is wrong with my car?

I guess I'll order the new filter assembly...

And if that does not help, I saw one slightly wrecked i30 nearby with a 3000€ price tag  . It would probably be cheaper to buy that and replace parts one by one until my car stars working and then sell the wrecked on to someone else. But with my luck I would just end up having two non-working i30s 

[Mike SX]

It's a driving nightmare, I hope you soon discover the problem(s).
Attempting different remedies can seem non exhaustive; unless you soon discover the LHM cause, you will discover an alarming number of LHM reasons, and may unfortunately never quite trust the vehicle again.
However, although Hyundai are not alone in LHM problems; specialist rectification knowledge is scant.
Keep us all posted 

[Dazzler]

I haven't re-read those links I posted but it wasn't the injectors that fixed the problem, think it was the fuel filter assembly ( a hairline crack is certainly a possibility I would imagine)

[Phil №❶]

The water issue is something that need immediate attention, so much so, that Hy put a warning light on your dash for that very reason. How sure are you that there was water. Before ordering expensive replacements, you should spend some money having your tank drained and the fuel lines / filter purged and then refill with good diesel. It may save you doing any other expensive repairs to your vehicle. You should also avoid the service station that sold you contaminated fuel. A fuel additive should also be used, to protect you from all these problems in the future.

If water gets past the filter and into the high pressure pump and then into injectors, the injectors can be blown to bits internally, as the water turns to steam, with injector debris passing through your engine, causing engine and HP fuel pump destruction, a very expensive repair.

[sundiz]

I am 80% sure there were few drops of water. But I mean that there were literally only few drops, not gallons of water. When I emptied the fuel filter to a container I saw few drops that did not mix with the rest of the fluid. Just like oil and water do not mix. But the amout was really small. But I guess that is enough to plug the fuel line. That and dirty filter could easily do the trick. The water warning light has never turned on during a drive.

Honestly I would have been suprised not to see couple of drops of water. Thats why there is a water separator. Usually the problem is not the bad fuel in here. Of course that happens, but the quality of the fuels is good in here generally speaking. Biggest problem is the condensation. In the fall time it usually rains a lot and the air is humid. The temperature variation during a day start to increase more and more when going towards the winter. If you have empty tank the moisture in the air condensates inside the tank. Especially when going near freezing point. I keep my tank usually full, but I have been driving quite a lot in the past few monts so the tank has not been always full. I drive my car 5-7 days in a week and keep it in a warm garage most of the nights which increases the possibility of a condensating water.

I have the old filter in the garage and I think I'm going to pop that baby open to see how contaminated that is on the inside.

I ordered the new filter assembly today. I was hoping to get it tomorrow so I could change it during the weekend. But I quess those parts are not so commonly needed, so they might have to order them abroad.

[Phil №❶]

Condensation is a serious consideration for all pilots, part of the pre-flight checks. If it is for them, it should be for all fuel injected car owners. When I first joined I started a thread about this, but the reaction was only warm to say the least. IMO, all Diesel vehicles regardless of brand should be fitted with dryer crystals in the fuel vent line which admits replacement air as the fuel is used. The crystals are cheap to buy and no matter how much moisture there is, your tank would remain dry. I strongly suggest that you use a Diesel additive which can deal with water, not only to eliminate it, but if allowed to remain in the tank, you run the risk of breeding Diesel bug which is a living fungus. It only lives on the Diesel water layer of your fuel but if left unchecked, eventually wreaks havoc with your fuel system.

Many owner's here do not use it and have never had a problem, a few have. I use it on our Diesel's as insurance against, water and the bug. It seems the bug is more prevalent here in Oz. It is an airborne problem and to be avoided like the plague. There should be a similar product in your country.

For your info, here's a link to the product I use, I have no affiliation at all with this company.

Microsoft OneDrive - Access files anywhere. Create docs with free Office Online.

[sundiz]

Diesel additives are likely to get someones attention  . Others say they are good, others say the destroy your engine... Personally I believe some are good and some aren't. I have now the "cleaning" additive in the tank. When the tank gets empty, I'll add some water removal. I would not like to mix two additive. Never know how they would act together.

I'll get an endoscope in couple of weeks. I'll have to check if it can handle chemicals (diesel) or not. If it does I'll take a look inside the tank to see if theres something that does not belong there.