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Hi Guys, I acquired an excellent 2.0 DOHC Sportage as part of a debt repayment. I say excellent . . Its a year 2000 4x4 manual transmission and the bodywork is spotless and so is the interior. I was told by the owner that it had been off the road for 6 months as it had starting problems. He said he'd spend £300 on trying to sort it out but all to no avail. Its got 63k on the clock. It will not start on the key but it does start with a tow. It seems to run ok but after 10 minutes its overheating. I did a compression test on it and it went 48, 38, 52 and 62 psi so I assumed the head gasket had gone. On dismantling I found that the thermostat was missing, the spark plugs are a great colour with no fouling. It seems the head had already been into the shop as it was spotlessly clean and came away from the block easily. The valves and oil seals have also been done. Its got a brand new cam belt on it and everything lines up. I swapped the head gasket as I had it off, reassembled and its still the same. I asked the previous owner and he said he was using it when it overheated. Diagnosed as head gasket he had the head skimmed and the valves done. He reassembled and its as it is now. Any ideas ? Why would all the cylinders have relatively low compression ? When running it sounds ok - ticking over. Any help will be appreciated.
 

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Well, it sounds like you checked the usual suspects, how did the cylinders look while you had the head off? I would probably pour a little oil down each cylinder and re-test compression to test if your rings might be the problem. If it makes no difference, there is only a couple options, the valve seats are not sealing against the valve, or just general timing. I would suggest going to kiatechinfo.com, and ensure you follow all the steps there for timing and adjustment. Finally, if that is in fact the case, double check the crankshaft gear has not sheared the key that holds it in alignment. That is all I can think of. Good luck!
 

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Your comment "It seems to run ok but after 10 minutes its overheating" bothers me The head may have been milled (skimmed) too far or it may still be warped and not sealing properly with the head gasket and/or block... Starting from cold...with the radiator cap off do you see bubbles when it's running? This is usually an indication of the head/head gasket problem...The exhaust gases are being pushed into the cooling system and overheating the coolant.

If the upper head is to "spec" (not too much skimmed off) and the valves are seating properly (not reseated too deeply as they may not close properly)...then you might have damaged/worn piston rings allowing excessive compression (blowby) to leak out through the "bottom". How about also excessive pressure at the oil fill cap? A little is normal..If a lot of the hot exhaust gases are getting past the piston rings (blowby) you can also experience overheating and lower compression (the gas/air gets forced by the rings also and the pressure reading will be lower..
Just some thoughts...
Dave
 

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Tuscani922...
You beat me to it! I was "composing" as you were posting...
We are both thinking the same thoughts!
Dave
 

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Ah YES the woodruff key on the crankshaft gear... Also!
 

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Discussion Starter #6
I'm just going to try the oil in the cylinders and compression check again. By running ok I mean it sits there ticking over nicely once I've got it started. Push starting it doesn't work it needs a good pull with another vehicle to get it going. If I turn it off after 5 minutes it won't start on the key. I had it running without the rad cap on yesterday and I don't recall seeing any bubbles just flowing water. Is it possible to pressure test the head with the valves and and camshafts attached ? this would tell me if it is the valves/sealing. I'll report back in a few minutes with the compression/oil test. Thanks for your input so far guys.
 

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Discussion Starter #7
Compression readings are no different so I don't think it is the rings. . . I think it must be something to do with the valves. . . they've definately been worked on.
 

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The overheating "may" be from a bad fan clutch and a secondary problem you found.
The Sportages in the USA have two fans. One electric between radiator and grill (AC fan) and one mechanical (belt/clutch drive) that is a REAL troublemaker as far as overheating.. You might want to wire the AC to run full time (two wires, +12v battery and ground/earth) and see if the temp goes down... Good sign of a bad mech fan.
We have threads here (kia-forums.com) on how to replace the problematic mechanical
fan with a temp controlled electric one.

The pressure cap (radiator cap) also can cause overheating if bad. Radiators and heater cores here (USA) are problematic also as their cores get plugged... The coolant will flow over the top but not through the plugged cores... A temperature camera or "gun" will tell if they are working properly by looking at the top/core/bottom and the hoses.

Your primary problem sounds like valves or crank woodruff key damaged. The key can get deformed and allow the crank gear pulley to move throwing off timing between crank and cams(valves).. Not as common as head problems though.
Dave
 

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Discussion Starter #9
I'm in the UK. I have both fans too and they are working well. I have also changed the rad cap. I'll take the rad off and give it a flush through see if that helps as I don't know anyone with a heat camera apart from my local Police helicopter ;). . I'll check the woodruff key next.. . thanks again for your help.
That Kiatechinfo site is good too thanks for putting me onto that.
 

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Discussion Starter #10
The woodruff key is ok. There is no play at all. The valve timing marks are all lined up nicely. From my analysis of all that I've checked and done I have to assume it is a problem connected to the valves. How can I check the valves ??
Thanks guys.
 

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The woodruff key is ok. There is no play at all. The valve timing marks are all lined up nicely. From my analysis of all that I've checked and done I have to assume it is a problem connected to the valves. How can I check the valves ??
Thanks guys.
Did you physically remove the crank cog and visually inspect the key-way...??

Low compression across the board is an indicator of poor engine timing.... Philip
 

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Discussion Starter #13
Thanks for your input Philip. I had to use a puller to take it off and it was a nice snug fit with no noticable wear at all. The marks on the crank cog lined up when the correct marks on the cam cogs were lined up (I on the inlet side and E on the exhaust both at 12 oclock) When the head was removed pistons 1 and 4 were at the top of their respective strokes. . .
 

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Discussion Starter #14
Thanks for your ideas and suggestions guys. I've been offered another engine at a good price so instead of throwing money and time at chasing faults I'm gonna swap the whole lump. cheers.
 

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I once diagnosed a valve problem with a vacume gauge. It was a long time ago but I think I put a T junction into one of the vacume hoses to run the gauge cause I didn't know if disconnecting that hose would cause a vacume leak in some other way. As I remember the gauge should remain pretty steady if all is OK. Google it cause this was in the days of carbs and my memory now is about as efficient as the carb was then.
Spellbound
 
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