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Omega Help Area => Omega General Help => Topic started by: magnul on 19 May 2008, 20:30:46

Title: Intermittent running rich at idle / Fault code 73
Post by: magnul on 19 May 2008, 20:30:46
After ~10kkm without any problems with my car, they're back and they're many :'(

First: I discovered (with my home made lambda monitor) that the engine was running rich at idle for >10seconds, causing the EML to light. If I give it a bit of throttle, the code disappears, and the car returns to closed loop. Paperclip gave code 73, Mass air flow temperature Voltage low. However, I don't believe the MAF is faulty. Checked the IACV, TB and breathers to the intake, but not much there.

Secondly: It's leaking oil like crazy. Probably lost 1-2dl while parked at work today. As it's oil everywhere, it's ompossible to pinpoint the leak, but pretty sure that it's higher up than the sump gasket. Can't see anything from the cam covers above manifolds in the front of the engine, but appears to leak massively in the back. Just checked plug wells, and they're flooded :(

So; are all the problems related? Is changing camcover gasket doable for someone like me? Most importantly: how to fix the cause? The gasket was done last year along with head gasket, so there's got to be something with crankcase pressure that causes it all?

-Magnus-
Title: Re: Intermittent running rich at idle / Fault code 73
Post by: philhoward on 19 May 2008, 20:39:27
If the plug wells are flodded, then the Cam Cover gasket is NO.1 suspect.  Excessive pressure is normally due to blocked breathers, although excessive blow-by will increase this to the point where the breathers can't cope.  If you remove the oil filler when its running, can the air coming out blow your hair about?

Just replaced my engine as my old one did (amongst other things..)...
Title: Re: Intermittent running rich at idle / Fault code 73
Post by: magnul on 19 May 2008, 21:04:39
Pretty sure the cam cover gasket is blown. Do you mean removing the oil dip stick or the filler cap? I have noticed lately that when I'm about to check the oil, the dip stick is not in its innermost position.
I wouldn't expect the blow-by in the cylinders is a problem. Had a compression test done last year and it was flawless. Perhaps it should be repeated.

Forgot one thing: What kind of sealant to use when replacing the gasket?
Title: Re: Intermittent running rich at idle / Fault code 73
Post by: magnul on 20 May 2008, 12:01:27
I got a new gasket from Opel today and will try to replace it this evening. At Opel they told me that they didn't use any sealant along with the gasket, so they couldn't sell me anything. Will any high temperature sealant (resistant to oil) do, or should I try without?
Title: Re: Intermittent running rich at idle / Fault code 73
Post by: albitz on 20 May 2008, 12:14:58
there is an excellent guide on changing cam cover gaskets (4 cylinder) on page 2 of maintenance guides :y
Title: Re: Intermittent running rich at idle / Fault code 73
Post by: magnul on 20 May 2008, 12:22:01
I've seen it, and the only clarification I need at present is the sealant :P
Title: Re: Intermittent running rich at idle / Fault code 73
Post by: albitz on 20 May 2008, 12:27:19
i know that on the 6 cyl. engines you must use a particular sealant,dont know about the fours though :-/
Title: Re: Intermittent running rich at idle / Fault code 73
Post by: Kevin Wood on 20 May 2008, 13:41:53
Quote
I've seen it, and the only clarification I need at present is the sealant :P

A sensor safe RTV sealant is what you're looking for. I've got a tube of loctite equivalent at home but can't remember the number.

Kevin
Title: Re: Intermittent running rich at idle / Fault code 73
Post by: Kevin Wood on 20 May 2008, 23:02:44
Just had a look and the sealant I've used before is loctite 598. Similar in appearance to the VX stuff and appears to do the job.

Kevin
Title: Re: Intermittent running rich at idle / Fault code 73
Post by: magnul on 20 May 2008, 23:28:55
I found a sealant that was supposed to be heat and oil resistant. Hope it's true, as I changed the gasket earlier this evening.

I don't fully understand the crankcase ventilation. I tried to start the engine with the breather hose from the crankcase disconnected, and to my surprise it appeared to be higher pressure in the cam cover than in the crank case. Do that make any sense?
Title: Re: Intermittent running rich at idle / Fault code 73
Post by: magnul on 21 May 2008, 07:40:22
When stopping after driving to work this morning I found that the rich at idle/FC 73 persisted. :'(

Also found a small pool of oil at the garage floor this morning. Hopefully the new gasket has fixed the oil in plug wells-problem, but appears to still be leaking oil at the rear of the engine. Are there any other potential places for leakage there?