- This topic has 18 replies, 4 voices, and was last updated 10 years, 7 months ago by
.
-
Topic
-
I was going down the road last week and my engine cut out. There was no warning, everything seemed fine, then off, it wouldnt start again. When I try to start it, the cranking sound is very fast.
Not quite sure where to go from, so I did a compression test on all 4 cylinders and there is absolutely no compression. There is no spark either.
I suspected a snapped timing belt, but when I look down the oil filler I can definitely see the camshaft (intake side?) turning when its being cranked. (Its a DOHC engine, not sure if the other camshaft is turning).
It sounds like a timing problem but I’m not so sure because the camshaft is turning.
What should be my next step in diagnosing and repairing this?
-
Replies
-
You need to put the engine back in time (the timing belt has jumped) and then check compression again to see if any valves are bent. If valves are bent the head needs to come off to be refurbished.
Since you didn’t tell us what kind of car it is or engine size I’m gonna guess that the timing belt has jumped and the only way to tell for sure is to remove the belt cover or timing cover depending on the engine.
Thanks for the responses 🙂
You need to put the engine back in time (the timing belt has jumped) and then check compression again to see if any valves are bent. If valves are bent the head needs to come off to be refurbished.
I watched Eric’s video where he adjusted the timing on the Honda but I’m not sure if that’s the same situation my engine is in. Firstly, this engine has the ignition coil packs on the spark plugs and therefore no HT spark plug leads to allow for a timing light to be connected.
Since you didn’t tell us what kind of car it is or engine size I’m gonna guess that the timing belt has jumped and the only way to tell for sure is to remove the belt cover or timing cover depending on the engine.
The car is a 2001 Renault Megane with the 1.6 16v DOHC engine with 93,000 miles. Its a FWD euro hatchback with a manual gearbox.
Service records indicate that the timing belt was replaced around 60,000 miles but it wasn’t done by myself or a Renault dealership so I’m not sure if the pulleys, tensioners or water pump were also replaced. Also, I’m fairly certain the engine is due a change anyway, regardless of mileage.I’m going to begin taking it apart tomorrow, how will I tell if the timing has jumped or if the valves are bent?
If the timing has jumped, how do I put it back in time? Would a Haynes manual cover this kind of thing?Side note: I do all the regular servicing on my cars and fix most problems by myself but I have never done a timing belt, my dad has though and I will ask him to help me out.
I don’t know the car or the engine. However, the first thing to do is to check if the engine is an interference engine or not.
An interference engine is an engine where the valves and pistons occupy the same space but not at the same time. So, if the timing belts jumps then the pistons and valves may try to occupy the same space at the same time. It is the valves that lose this contest. Bent valves would cause zero compression.
If not an interference engine then the above can’t happen.
So do some research and let us know.
Yes it is an interference engine.
I found a kit on eBay which includes the head gasket, 8 intake valves, 8 exhaust valves, 10 cylinder head bolts and a timing belt kit for £125 (around $200). If this is everything that would potentially need replacing I will go for it.
I have a 2004 WRX, nice little car but needs more suspension. I wish it was the STI or at least had the STI suspension. Hmmm. another garage project.
Yeah, it sounds like a nice kit but there is still the problem of why the belt jumped or broke. So, you may need additional timing belt parts. Also, there is the no spark issue. Maybe the belt took out the crank sensor. That or one of the cams (the one with the cam sensor) is not moving.
Occasionally these incidents can be more serious. Have you had the spark plugs out and looked at them and also looked into the cylinders? (Edit – dumb question, I see that you have done compression.) I’ve seen everything from where there was very little damage (the engine was put back in time and ran fine) to where the valve heads broke off, the spark plugs were destroyed and the insides of the cylinders looked like aluminum jelly.
It is not much money so maybe you want to go ahead and get the parts on order. However, if it was me, I’d want to first see how badly the belt timing is screwed up and see what can be seen inside the cylinders – get as much information as you can before spending money.
If it jumped time as suggested, it may bend the valves and cause the compression loss. Let us know what you find during your exploratory. If it’s in time, you may be flooded. If that’s the case, remove the spark plugs and let them and the cylinders air out. Also, when you go to start the vehicle after you reinstall the plugs, hold your foot to the floor on the gas. This will turn off the injectors so it doesn’t add more fuel. You may have to crank it for a while before it builds compression again. Try not to do it for too long however as you can burn up your starter doing that.
My bets are that it jumped time. Keep us posted on what you find.
One last thing. If it did jump time. Just reinstall a new timing belt and recheck for compression. Even if you did bend valves you’re still going to have to replace the belt anyway. You might as well take a chance. Who knows, you might just get away with it.
Good luck.
I have a 2004 WRX, nice little car but needs more suspension. I wish it was the STI or at least had the STI suspension. Hmmm. another garage project.
Yeah, it sounds like a nice kit but there is still the problem of why the belt jumped or broke. So, you may need additional timing belt parts. Also, there is the no spark issue. Maybe the belt took out the crank sensor. That or one of the cams (the one with the cam sensor) is not moving.
Occasionally these incidents can be more serious. Have you had the spark plugs out and looked at them and also looked into the cylinders? (Edit – dumb question, I see that you have done compression.) I’ve seen everything from where there was very little damage (the engine was put back in time and ran fine) to where the valve heads broke off, the spark plugs were destroyed and the insides of the cylinders looked like aluminum jelly.
It is not much money so maybe you want to go ahead and get the parts on order. However, if it was me, I’d want to first see how badly the belt timing is screwed up and see what can be seen inside the cylinders – get as much information as you can before spending money.
Thanks for the response.
Yeah, of all the cars I have ever driven, the Subaru in WRX or STI version is my absolute favourite car to own and drive on a daily basis, I’ve driven much more expensive and exotic cars around the track but nothing beats an STI or WRX on coilovers. If you are looking for a project, don’t make the mistake of trying to upgrade a WRX to all the STI parts but a decent set of coilovers make the WRX less “boaty”. :cheer:Anyway, my spark plugs look completely normal, I put them in myself around 10,000 miles ago, they’re Bosch 4 electrode plugs and they are dry and slightly carbonated – nothing unusual.
If it jumped time as suggested, it may bend the valves and cause the compression loss. Let us know what you find during your exploratory. If it’s in time, you may be flooded. If that’s the case, remove the spark plugs and let them and the cylinders air out. Also, when you go to start the vehicle after you reinstall the plugs, hold your foot to the floor on the gas. This will turn off the injectors so it doesn’t add more fuel. You may have to crank it for a while before it builds compression again. Try not to do it for too long however as you can burn up your starter doing that.
My bets are that it jumped time. Keep us posted on what you find.
One last thing. If it did jump time. Just reinstall a new timing belt and recheck for compression. Even if you did bend valves you’re still going to have to replace the belt anyway. You might as well take a chance. Who knows, you might just get away with it.
Good luck.
Thanks for the response Eric.
Before doing the compression test, I tried holding the throttle wide open and cranking with the plugs out even though the plugs were dry, I also let the cylinders air out over night, I don’t think its just a flooded engine because that wouldn’t explain the lack of spark.
I had to go buy a female torx socket set to get the intake manifold off, it sits atop the cam cover.
With that off and the throttle body out of the way, I can see that both camshafts turn when the engine is being cranked which I can only assume is a good thing. Gave up working on it today after I finally managed to remove the throttle body (such a stupidly designed intake!), I removed all the bolts from the cam cover but I couldn’t get it off. It looks as though its been sealed with some type of black gasket sealer which has glued it on. It was cold outside and I didn’t wanna wrestle with it anymore.Once I get to the timing belt cover, is it just a case of getting the first cylinder to TDC, lining up the cam and crank marks and fitting a new belt and then checking for compression?
Thanks for all the help so far guys, much appreciated 😉
Once the timing cover is off, turn the crank to top dead center and check if the cam timing marks line up or are close. If they are way off turn the crank another 360 degrees.
As for how you do remove the timing cover, since I don’t know the engine I have no idea. Every engine is different and all seem to include some gotcha.
So get the cover off (obtain a copy of the SM if necessary) and see if the belt has jumped by examining the timing marks. Let us know what you find.
Just because both cams were spinning that doesn’t mean that they’re in time. If they’re not in time, you can loose compression. To know for sure if that’s the case, you need to verify the marks. Sounds like you’re on that path.
Keep us posted on your progress.
This morning I got the timing cover off which was a PITA!
Part of the engine mount is also the timing cover and there is little working room.
I’m not sure where to go from here so I have included some images for your viewing pleasure 😛This is the engine bay of the Megane with the intake manifold, throttle body and ignition coils removed:
After supporting the engine with a jack, I removed the engine mount which acts as part of the cover… this is what I found:
Also removed the cam cover:
It appears that the intake camshaft pulley’s guard has sheared off and become mangled between the pulley and the belt. The one on the exhaust side had come off too but it hadn’t interfered with the belt:
Here is the cam cover: On the left is the camshaft seals and on the right are the tappets which had come loose in the top part of the engine, only one of them looks damaged.
So that’s where I stand at the moment… I’m not sure what caused the guard to come off. It looks as though the tappets and the camshafts took the damage. One tappet has been chipped and the exhaust camshaft looks cracked. Not sure if it is possible to say the valves are OK without removing the head though.
Not sure what to do now… should I buy the special TDC setting pin and camshaft locking tool from Renault?
I suppose its OK to remove the belt and camshafts without setting it to TDC?I’d worry about the special timing tools later.
First, is the jack holding up the engine one that doesn’t leak down? The reason I ask is because it is going to be there awhile. I’d suggest checking every day that the engine is not headed toward the ground.
At this point you should consider obtaining a copy of the factory service manual or at least some aftermarket service manual. If nothing else you will need the torque settings.
Pull the timing belt, pull the cams. Be very careful with the cam journal caps. They have to go back on in the same place and oriented the same way. Do whatever you have to do insure this happens.
If stuff is knocked loose on top of the head the valves hit the pistons. The only other thing that could possibly do this is way over reving the engine and valve float. So, the head needs to come off. Next, check the condition of the pistons. Nicks and gouges can be smoothed out but look for cracks. Cracks require replacement pistons which may mean total overhaul.
This is the time to stop and figure out the cost of repair and compare it to the cost of a used or refurbished engine.
Assuming you decide to continue, the head needs to go to a machine shop for refurbishment. Meanwhile, you acquire the other parts that need replacement.
I hope this helps.
[Edit: I’d turn the crank to TDC just to see how far the cam sprocket(s) skipped. There’s no real reason to do this now since we know it skipped. However, every story I’ve heard about a misadventure like this always starts with, “and then my cam skipped X teeth”. So, you need this information for the story. 🙂 ]
Hmmm, just thinking, it could be that the first thing that happened was the exhaust cam breaking. They never seem to break if the timing belt jumps but only in normal driving. Metal fatigue I guess. If this allowed the sprocket to move around a little it then could then have taken out the guard. Like I say, just a thought and looking at your pictures I’d say not likely.
The valve system in your engine is identical to the Mitsubishi engine in the Evo.
BTW, my WRX is trying to turn into a DSM (If you don’t know about DSMs they were notorious for breaking down). I had a cooling hose leak and fixed that. I went back to check the coolant level and found the radiator was leaking. Replaced that. Went back today to check the coolant level and found the pressure hose for the power steering was leaking.
Hi Barney,
I guess its difficult to determine exactly what when wrong first.
What does the Evo valve system have in common with the Renault one exactly? That sounds really interesting.
That sucks about your WRX, they are rather high maintenance cars tbh, very difficult to justify owning one financially but the fun factor is awesome.
As for Meg, I put the engine mount back on it before I left it last week, I haven’t had time to work on it since, it sucks because I can’t get it into my garage because its on an incline and the ramp is also steep, so I’m having to work at the side of the road.
I’m not sure if I have afford the time and money on parts to fix it at the moment, I kinda dont wanna pull the head, in the past where I have had heads machined and refit the engine hasn’t run the same again and has had a limited lifespan.
In the meantime, I bought a 2000 Toyota Yaris (Vitz? Echo?) 1.3L with 163k miles… not sure if it was such as a good idea yet, the exhaust is leaking and the rear springs need replacing, among other smaller problems. Way more miles than Meg but no rust on the underside and wheel arches. Its been serviced religiously and its a freaking Toyota!
I drive an Evo and seeing the insides of your car’s head I was surprised by the resemblance. Both engines, it appears, have roller cams and hydraulic lash adjustors. They look nearly the same.
The Evo people drag racers run these things to 10,000 rpm with mild valve train upgrades. As for the WRX, I think the company spends too much money on their complicated engine design and maybe has to make up the difference elsewhere. The quality is not the same.
Anyway, I understand you hesitance. Sometimes its better to have a driver than a big expensive project.
Thanks for getting back to us and best of luck with the new ride.
- You must be logged in to reply to this topic.