hyundai sonata timing belt may have thrown!!!!

[Mark]

05 Hyundai sonata 2.4L
(I know its kinda a story sry)
Situation stands as follows:
While back I put a timing belt on my cousins car. Had issues getting all back together but got it after finding that the tensioner was faulty. Changed the belt and tensioner assembly and threw it back together. Car Ran fine. (a very slight tick but we deemed it not bad enough to go in a re time it.) Anyway about 1k miles later he told me that the oil light came on while driving so I told him not to drive it and check the oil to see what was up. It had oil yet the light was on so we figured it could be a sensor issue he drove it for at least 50 miles with the light on (so I figured if it had no pressure it would have seized ages ago.
Today He said he was driving on the highway (oil light on) and he heard a noise then some clunking and the car just stopped. I haven’t seen the car yet but im trying to figure the chance that the belt slipped? reason why we didn’t think anything of the light was cause I knew that all the pump had to do was turn to gain pressure so I figured the belt was fine. If the belt didn’t slip could the oil pump have failed and the noise was the engine loosing lubrication? If the belt DID slip then im thinking about re doing the timing belt and pullin the head to see the cylinders (hope they are fine) and just have the valves changed. (interference engine)

So questions to some this up would be
1. What is your opinion on this short story here?
2. What are your experience with thrown timing belts and if you can just put in new valves if they bent and belt and call it a day?
3. Explanation for the oil light??? Maybe there was a sensor issue and the belt threw? I was very sure of the belt when it all went back, I spent alot of time on it and test drove it for a good 12 miles before handing the car back.
4. Why would the belt throw and chances that it slowly loosened somehow?
5. Chances of oil pump failure?

Thanks for your time, sry for the long post but Its good for me to type this out anyway it gets me thinking I suppose. Will update when I see the car. Thanks again.

Topic

[JamesB1985]

Really it would be better to check out the car first so you could give us a lot more information, or were just guessing really.

First thing I would do is check to make sure oil is at the proper level when you get the car. After that I would check the timing to see if everything is in time. Did you replace the Balance Shaft belt too? I believe there both supposed to be changed at the same time.

I think your on the right track with the tensioner being the culprit though because if it was driving fine then the tensioner started losing tension on the belt it wouldn’t crank the sprocket to drive the oil pump at the proper speed which would cause low oil pressure hence the oil light. I’m doubting just straight up oil pump failure.

Usually you can just change the valves if they hit the pistons but obviously check for damage on the pistons and cylinder walls. From what you say happened/heard it sounds like that’s what happened with clunking noise. Let us know what happened!

[Its me]

[quote=”autotech09″ post=68113]05 Hyundai sonata 2.4L
(I know its kinda a story sry)
Situation stands as follows:
While back I put a timing belt on my cousins car. Had issues getting all back together but got it after finding that the tensioner was faulty. Changed the belt and tensioner assembly and threw it back together. Car Ran fine. (a very slight tick but we deemed it not bad enough to go in a re time it.) Anyway about 1k miles later he told me that the oil light came on while driving so I told him not to drive it and check the oil to see what was up. It had oil yet the light was on so we figured it could be a sensor issue he drove it for at least 50 miles with the light on (so I figured if it had no pressure it would have seized ages ago.
Today He said he was driving on the highway (oil light on) and he heard a noise then some clunking and the car just stopped. I haven’t seen the car yet but im trying to figure the chance that the belt slipped? reason why we didn’t think anything of the light was cause I knew that all the pump had to do was turn to gain pressure so I figured the belt was fine. If the belt didn’t slip could the oil pump have failed and the noise was the engine loosing lubrication? If the belt DID slip then im thinking about re doing the timing belt and pullin the head to see the cylinders (hope they are fine) and just have the valves changed. (interference engine)

So questions to some this up would be
1. What is your opinion on this short story here?
2. What are your experience with thrown timing belts and if you can just put in new valves if they bent and belt and call it a day?
3. Explanation for the oil light??? Maybe there was a sensor issue and the belt threw? I was very sure of the belt when it all went back, I spent alot of time on it and test drove it for a good 12 miles before handing the car back.
4. Why would the belt throw and chances that it slowly loosened somehow?
5. Chances of oil pump failure?

Thanks for your time, sry for the long post but Its good for me to type this out anyway it gets me thinking I suppose. Will update when I see the car. Thanks again.[/quote]

1. NEVER EVER, EVER, EVER, EVER, EVER, EVER, EVER drive a car with an oil light on a second more than you have to. Consider the oil pressure to be low to damaging levels until proven otherwise (with a mechanical gauge test)… Until then, you can do immeasurable damage to bearings, rings, valves, cams, etc…. You just learned that lesson the hard way….

2. I have seen several thrown belts when Camshafts break… And guess what the #1 cause of Camshaft breakage is….. LACK of LUBRICATION. If you have bent valves don’t even count on being able to save the engine, you may have other issues… Such as damage to Pistons, damage to cylinder (pieces of valves)….

3. The oil light can be on for many reasons: low oil, low oil pressure due to bad bearings, bad oil pump, clogged oil passages, sludge in oil pickup…. How does much of this happen… People don’t change their oil on the vehicle in a timely manner… In fairness though, some engines collect more sludge than others…

4. Can you get the engine to turn (by hand or starter?) If it doesn’t there is a very good chance you have locked up the engine with a piece of valve wedged in the cylinder or a thrown rod…… The timing belt situation is probably one of the least of your concerns….

5. I am pretty sure this is an interference engine.. Therefore if your belt was thrown some valves are probably toasted… Some pistons heads might be toasted as well.

6. If your belt wasn’t thrown as stated before I would be severely concerned about a spun bearing or thrown rod… These can easily happen when you run an engine with low or no oil pressure…

7. With the sound the car made before it died, there is a very good chance this engine has run its last mile…..

Good luck

Karl

[richiepearce]

1) Could be oil pump internals breaking up. Oil strainer blocked needs further investigation.

2) I have seen interference engines that just needed valves but also seen them that have holed pistons. On a positive note I have also seen interference engines where no damage has occurred.

3) See (1)

4) Don’t get caught up in the belt issue, just because it has had that work done does not mean that will be the cause of this failure, further investigation required

5) It does happen.

[college man]

You either have a faulty oil pump or the oil
sensor is bad. you would have to test oil pressure
with a gauge.

[richiepearce]

I certainly would not advise ANY tests which involves cranking the engine via the starter motor until, you ascertain that the engine has not seized and is mechanically ok to be cranked.

[Its me]

[quote=”richiepearce” post=68147]I certainly would not advise ANY tests which involves cranking the engine via the starter motor until, you ascertain that the engine has not seized and is mechanically ok to be cranked.[/quote]

+1…. In the event you have a thrown or broken belt and the valves are still not smashed, you don’t want to smash them..

I would ask whoever was driving it if they tried to start the car after it stopped. If the starter could no longer engage or the lights just dimmed then you know pretty well the engine is locked up.

Attempt to rotate the engine with a breaker bar clockwise very, very slowly and see if you feel hard resistance/the engine cannot be turned anymore. Some resistance is to be expected when turning the engine through compression stroke but stop immediately if you feel hard resistance or hear anything unusual….. Also, if can view the valvetrain (through an oil access) or with the valve cover removed, see if the camshaft is still moving (and in one piece)…. If you can complete a full 360 degree rotation of the crank you may have dodged a bullet….

-Karl

[Mark]

Thanks for all the advice here guys. Unfortunately I still haven’t been able to look at the car. It looks like this will be out of my hands now anyway since it seems another shop will tear into it.I still don’t understand how the belt could have thrown. Specially since the car was driven fine for a good while before this happened. Unless the tension assembly failed AGAIN! (it was changed due to inaccurate tension when the job was first done).

[Author]

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