Not a good weekend for me

[admin]

So this past week and weekend I found out that my daily driver (2005 Jeep Wrangler TJ) may have just taken a turn for the worse. I was traveling down my normal commute when out of nowhere the engine just dies. Somewhat luckily I was at a cruising speed so I was able to quickly throw the clutch in and bring it to a safe stop while in neutral. At this point I had no engine code thrown, but that changed as soon as I attempted to start it up again. The check engine light started flashing (never a good sign) and despite it turning over I was getting no hope of it firing up.

Come to find out the code thrown was for the Camshaft position sensor. Ok I can deal with a sensor going bad and the research shows these tend to go out around 100k miles. Well I'm in the mid 90s so 50 dollars later I have a new weekend project. Saturday I easily find and replace the sensor yet the engine still wont start. In fact I attempted to clear the code and it still kept coming back. This is when I started getting a sinking feeling.

I get a second set of hands and have them "bump" the engine over as I keep an eye on the timing belt and cams. Nothing moves!!!! The timing belt jumps ever so slightly but I get no real movement. You know that sinking feeling, well its getting worse. Now I'm thinking worse case scenarios, Did I just blow up the engine? At this point we do a red-neck tow to get the jeep into a local shop. When I say red-neck tow I mean we had a tow/recovery strap hooked up to my bumper and going to a little Subaru. The other driver was the "engine" and I was the "brake". Needless to say I was glad the shop was only a couple of miles.

The shop confirmed the timing belt has stripped so there was a portion about 4" long with no teeth on it. As soon as that hit the drive gear the timing stopped and everything went out of alignment. Which now also explains the camshaft position sensor. The cams werent turning so the sensor wasnt getting any signals.

Now the hard part...did the timing go out in such a way that it damaged the engine internally??? I'm assuming yes because I'm assuming its an interference engine and since I was at speed when it died I can only assume the piston and valves had a not so friendly meeting. Unfortunately I cant know this for sure without some major work and the local shops are quoting at least 500-600 dollars just to do the timing belt job. If more damage is found the cost could easily double or more!!!!

I luckily have a friend with advanced mechanical skills who is willing to help me do the timing job which will save at least 300+ on that portion, but we still may end up needing a lot more work if the valves are bent or the heads are damaged.

I'm mostly venting here because I dont know what else to do...I bought this used from a dealer just after the 60k mile mark and it never occurred to me to specifically ask about its most recent major service. I'm willing to bet it never had a 60k mile service and in turn I'm also willing to guess that this is the original timing belt. Either way I now have a daily driver with less than 100k miles, that may essentially need a new engine or at the very least, some major mechanical work.

I feel like i'm going through the stages of grief...............Here's to keeping my fingers crossed that no major damage was done  :|

[tinkeringtechie]

Bummer    Usually when pistons and valves collide it makes a horrible noise. Do you recall hearing anything when it died? Also, does the Jeep really require a new timing belt at 60k? That seems pretty frequent to me... I'm used to 90k+

[djsamuel]

Don't be so sure about it being an interference engine.  What engine is in there?  If it is the 2.4L, that is the same engine as my PT Cruiser, and it is NOT an interference engine.  I have over 316,000 miles on that engine and have changed the belt three times so far (never broke, just maintenance).

Worst case would be to buy a rebuilt head and replace it.  Not a bad job, and not too expensive.

[david]

Here is a simple test that will tell you if it is an "interference" engine or not:

After you remove the timing belt, put an appropriate size socket wrench on the camshaft drive shiv. Then turn the camshaft. If it will make a complete turn then it is highly unlikely that the engine scrambled the valves. But there is a slight chance that the valve heads broke off and now it turns easily. The next test is to turn over the engine by hand, probably after putting on a new belt and aligning the timing marks. If it will turn a complete turn then you are almost certainly ok.

I would do the two test whether they tell you anything about the internals or not. They assure you that nothing is scrambled and  trying to start the engine might make it worse.

David

[leslie]

I hate it when stuff like this happens. 20 years ago, I lost the timing belt on my Mercury - several teeth gone. Luckily, the engine wasn't damaged. The water pump was, but that was a repair I could afford. Those Wranglers are tough. Hopefully, your damage will be minimal.

[spot1]

If it's a 2.4L engine, supposed to be a non-interference engine. Hopefully all you need to do is replace the timing belt. 

Check out this thread:

http://www.jeepforum.com/forum/f9/broken-timing-belt-2-4l-help-978234/

[djsamuel]

As I stated above, the 2.4L is a non-interference engine.  The only possible (although rare) damage in the event of a broken timing belt is valve to valve contact.  I've only heard of that happening once out of MANY broken timing belts.  But don't rotate the cams to make sure you don't get valve to valve contact and inadvertently bend a valve.  If there is valve damage (I HIGHLY doubt it) you could just purchase a rebuilt head, or have yours rebuilt.  There would be no damage to the short block at all.

If there was slight valve damage you would hear it when cranking the engine over after replacing the belt due to compression loss. It won't sound normal when turning the engine over.

The only caveat with the 2.4L is the make sure you have the timing marks aligned correctly.  If the exhaust cam is off by one notch, it will idle lousy, but will not throw a code since the cam position sensor is on the intake cam.  It can be tricky to align.  If you are not sure if it aligned, it probably isn't.  You will know it when it is right.

May as well change the water pump, tensioner, and idler while you have it apart.  I get the full kit from Gates and it is good.

[admin]

I have seen several places saying the 2.4L is a non-interference engine which has my hopes up. Then on the flip side I've had almost as many places list it as an interference engine so I honestly dont know what to believe.

DJ I'm guessing its the same 2.4L as the PT Cruiser since I think this engine was used in a range of cars as well as the jeep.

TT I dont recall any nasty sounds when it died, and I was able to get it out of gear very quickly.

David one of the shops did a similar test while looking at it and at this point it freely turns over by hand and the tech said he felt no resistance so that has my hopes up. On the other hand I've had people say it could simple mean the valve got rammed up and out of the way.

Exploring...that was actually the thread where I grabbed the instructions for the job It raised my hopes a bit, but it seems every site and person has a different idea about these engines.

I am starting to think the confusion is because the 2.4L is non-interference yet the 2.5L is interference and people are mixing the two together...just a guess though.

Sounds like no matter what its going to be a guessing game until I get the timing repaired and test it out.

Side note, from a DIY perspective its annoying when a repair kit is sold in two versions. Both with the same exact parts except 1 kit has the pulley already on a bracket and the other kit does not.

[admin]

As I stated above, the 2.4L is a non-interference engine.  The only possible (although rare) damage in the event of a broken timing belt is valve to valve contact.  I've only heard of that happening once out of MANY broken timing belts.  But don't rotate the cams to make sure you don't get valve to valve contact and inadvertently bend a valve.  If there is valve damage (I HIGHLY doubt it) you could just purchase a rebuilt head, or have yours rebuilt.  There would be no damage to the short block at all.

If there was slight valve damage you would hear it when cranking the engine over after replacing the belt due to compression loss. It won't sound normal when turning the engine over.

The only caveat with the 2.4L is the make sure you have the timing marks aligned correctly.  If the exhaust cam is off by one notch, it will idle lousy, but will not throw a code since the cam position sensor is on the intake cam.  It can be tricky to align.  If you are not sure if it aligned, it probably isn't.  You will know it when it is right.

May as well change the water pump, tensioner, and idler while you have it apart.  I get the full kit from Gates and it is good.

I was looking at the Gates and AC Delco kits...any chance you know why one version has the tensioner and idler on brackets and the other version of the same kit does not?

[admin]

ended up getting the one where it was pre-mounted on a bracket. I talked to a local NAPA and they said I could always just unbolt the new one from its bracket if need be. Plus the pre-mounted kit was a bit cheaper for some reason...

Amazon came in at under 100 dollars for the kit

[spot1]

With your friend's help, hopefully there will be no other issues and you will be up & running this week!  

[djsamuel]

[quote timestamp="1415653906" source="/post/4968/thread" author="@admin"]ended up getting the one where it was pre-mounted on a bracket. I talked to a local NAPA and they said I could always just unbolt the new one from its bracket if need be. Plus the pre-mounted kit was a bit cheaper for some reason...

Amazon came in at under 100 dollars for the kit [/quote]I always get the one with the bracket.  It's just easier.  I've changed the belt on these engines quite a few times.  It will be fine.

[spot1]

Sean,

Curious if you have the Jeep back up & running?

[admin]

Just completed the work this weekend A buddy and I started the project late Friday night and it took about 2.5 to 3 hours to complete. It was a surprise to me how "easy" it was compared to what I expected.

We had to remove essentially everything from the front of the engine. This included moving the AC compressor, alternator, drive belt, various pulleys, brackets, and covers. To be honest, I have had more difficulty accessing parts to change to oil on some cars compared to this. Keep in mind this engine takes up a fraction of the engine bay, so we had plenty of room to get in and work.

The cams were still in time due to the way the belt failed so the only real concern was making sure the crank was back at top dead center when the belt was replaced. Even that wasnt difficult since the crank pully and case were well marked for top dead center.

I also purchased a subscription to alldatadiy.com which is a vehical specific subscription to the same information many shops subscribe to. If I had been doing this alone it would have saved me a ton of frustration, but with the help of my friend it was more of a torque spec reference.

All in all djsamuel was right, this is not a bad engine to work on for this job, and I'm still excited that I didnt blow up my engine. Oh and saved at least $400 or more over going to a shop.

[djsamuel]

Glad to hear it worked out.  These engines are basically bulletproof, so apart from these "hicups", they keep on running.  Like I said, over 317,000 miles on mine and still going strong.

Doug