15 replies to this topic

[ScoobyPaul]

Hey guys, seems I can't go even 12 months without a problem. The car had been running brilliantly after the reco engine went in during January. Sunday it suddenly lost compression, idles really rough, has bugger all power and became a pig to drive. Wouldn't accellerate anywhere near what it used to (not that it was a rocket ship by any means, but the difference is clear.)

I took it to a good local mechanic today and he's scratching his head. The compression on the passenger side cylinders is 180psi, the drivers side measured 120psi. The injectors are getting pulse and there's plenty of spark from the leads (I replaced the leads and plugs a few months ago, so they shouldn't be the problem). He suspected a the timing belt may have jumped a notch, but the vacuum test didn't show anything amiss. Mind you, I'm not familiar with a vacuum test, so I don't know what it does and I don't know if it would show if the timing was out.

From doing my research on here and other sites, I can see it's an interference design, which leads me to believe that if it had jumped a tooth, then it's likely I would have damaged valves. But when that happens it's a rather audible affair, I have not heard any bangs, clunks or anything like that. The only difference is the exhaust note is lumpy (kind of like it has an aftermarket exhaust) and the engine shakes a lot, almost like it has a stuffed engine mount, which it doesn't have.

I'm unsure of what to check next, could testing for injector pulse have no bearing on whether or not they're actually squirting fuel? Could it just be faulty injectors? Not having done a compression test myself, does the pressure reading come from when the engine is running? Does anyone have any idea on what we should look at next?

The pulleys are all ok too, no problems there.

Cheers all, I'm really stumped and this is my everyday car, so any help that can be offered will be greatly appreciated.

-Paul

[Scuba-Roo]

When my timing belt jumped teeth I didn't hear any knocks, I never did the compression test myself but the workshop I took the car too said my compression was fine. new timing belt and re adjusted the timing and my car was fine, I was so lucky!


Is it possible that your valves are out of time and staying Slightly open causing the low compression?

[ScoobyPaul]

That's precisely where my train of thought has been headed. I asked him if it's possible to be out like that and he said it was, but then said the vacuum test would have shown if there was an overlap of timing. I could only take his word for it as I've never conducted a vacuum test myself and don't know what they show and how they work.

I'll give him a ring again and let him know your story. Could well be a very similar thing. Thanks for that

[RX25SE]

Did he pull the cam covers off and take a look?

Sounds VERY much like a cam timing issue on one bank.


Vacuum test is good for a pointer but the only way to confirm the cam timing is OK is to look at the timing marks.


Is it twin cam?



Edit:
I would think that the vacuum readings would be different to a 'normal' engine as one (or two) cams is only running half the engine.
Should the cam belt jump on say a inline 4cly, it would effect all cylinders.

[Xon]

Kind of sounds like it could be a head gasket?

[fatcat67]

Sound like a timing issue.
If its only jumped a couple teeth the valves might'nt have contacted the pistons yet.
Make sure the tensioner is in good order when you look at it and that none of the idler pullies have siezed ar are tight.

[Alex]

I will also agree on timing belt based on the symptoms you have described.

Did you use a new timing belt kit when fitting this motor?

[B4TT]

How annoyance.

Hopefully you get to the bottom soon, does very much sound like a timing issue though.

[ScoobyPaul]

Definitely a timing issue. My mech had a chance to sleep on it and with a clear head he had another look today. It's out by about a 1-2 teeth.

New timing belt kit is going on today and I said to replace the hydraulic tensioner regardless. I know it *might* be ok, but I'd rather be safe than sorry. Knowing my luck, if I don't do it to save cash, it'll bite me in the arse later when it all goes to poo lol.

A sincere thank you to all for your input, it has been really helpful in getting to the bottom of this.

Interesting thing to note, the problem occurred at my mate's property, and I had to drive from Kandos to North Richmond on only 2 cylinders and it coped quite well...tough motor!!!

[RX25SE]

Good idea to clean and lube the tensioner arm pivot.

[B4TT]

I always replace the water pump if I am doing the timing belt

[RX25SE]

^^^

Oh yeah, that too.

[B4TT]

[ScoobyPaul]

Good advice!

#1 on the ignition coil has packed it in today. *screams*

Looks like I'm on the hunt for one of those now too. If anyone knows of one available, please let me know

[RX25SE]

Good advice!

#1 on the ignition coil has packed it in today. *screams*

Looks like I'm on the hunt for one of those now too. If anyone knows of one available, please let me know

Replace both coils if possible, and the leads.

[ScoobyPaul]

Sourced a set, so it's all good. The leads and plugs are only about a month old though, I replaced them as part of regular servicing.