REplace rods and mains? HELP

[geo_allino]

Hey gurus,

I got a 1991 Esprit, when the oil gets warm I get real low oil pressure during idle. the red light does not come on much, but I am not comfortable with it.

Is there someone that wants to make some bucks and drop the pan and replace some bearings.

Is it possible to change the mains and rods without dropping the crank?

I can drive to where ever there is someone that wants to make some extra cash money working on my car.

Please message me by e-mail:
[e-mail] I will be sure to get it that way.

I am driving across the country so I can stop off anyplace and let you work on it and get it all turned and running good, all I want is a decent price and stuff.

If there is anyone that likes and knows this car and wants to make some money It would be great.
and I am a decent mechanic myself, I just dont know this car.

[e-mail]

[Paula&Marcus]

Hi Geo,
My advise is
- renew your engine oil and filter to proper spec. Castrol RS 10W60 or Mobile 1 W50 (the high viscosity number should not be lower than 50 !!!)
- recheck your oil pressure by using a mechanical gauge. Maybe its just your dash gauge or sender that is a bit inaccurate.

Cheers
Marcus (www.PUKesprit.de)

[Lotusguy]

geo_allino said:

Hey gurus, I got a 1991 Esprit, when the oil gets warm I get real low oil pressure during idle. the red light does not come on much, but I am not comfortable with it. Is there someone that wants to make some bucks and drop the pan and replace some bearings. Is it possible to change the mains and rods without dropping the crank? I can drive to where ever there is someone that wants to make some extra cash money working on my car. Please message me by e-mail: [e-mail] I will be sure to get it that way. I am driving across the country so I can stop off anyplace and let you work on it and get it all turned and running good, all I want is a decent price and stuff. If there is anyone that likes and knows this car and wants to make some money It would be great. and I am a decent mechanic myself, I just dont know this car. [e-mail]

Hi,

It's really much more diffcult to try and replace the Big-end and Main bearings insitu, and not recommended.

First, you'd need to mic the crank to know if you needed standard or oversized shells. Next, if the issue you describe is bearing related, the crank would possibly be scored and require machining. Finally, there is no way to measure end-play or runout with the engine in place.

Before considering such a major repair, perform the maintenance that Marcus has suggested and see if the problem really lies where you think it does. The 907 engine has a massively overbuilt bottom end and failures there are extremely rare. My bet; you have a bad pressure sender or an electrical gremlin in the gauge circuit.
Happy Motoring! ...Jim'85TE

[judson]

Just a clarification...
The 910 bottom-end is much more bullet-proof than the 907 bottom-end.

Besides the physical differences, the 907 used 360^ grooved bearings which have a lot of side-leakage at higher pressures & rpms. These early engines show wear in the mains before the rods (when the mains get worn the rod bearings starve and self-destruct).

Later 910/912 engines use x-drilled cranks and 180^ grooved bearings. There is plenty of evidence on the web (Clevite, etc.) to explain why 180^ mains are superior. Bottom line, better wear and more pressure on the mains protects the rods.

Specific to low pressure readings...
It's not uncommon to see low numbers on 907 or 910 variants when hot...check the spec...it's something like 5psi at idle and 45psi at 6000rpm...someone please clarify for me...

I chased oil pressure problems for years in my 907 assuming it was a bearing problem. It was actually a mix of problems (worn oil pump, blow-by overheating the oil, etc.).

What to do about it....
The rod bearigns can be replaced by pulling the pan, but I don't recommend it. Labor and parts could easily exceed $1000 and there's no guarantee it will make any difference.

As was previously mentioned, for best results, the crank should be turned and matched to replacement undersized bearings. If you go this route, it makes more sense to rebuild the entire engine.

I'd suggest flushing the oil numerous times to clean out all of the sludge. At $200, replacing the oil pump rotors is fairly cheap and easy and would give you instantly more volume and pressure.

If you want to drive to Atlanta, I'd be more than happy to change your rods and take your money!

good luck!

[maigret]

I replaced the annulus in the oil pump last year which brought the clearances back within spec.

Cost including freight was less than $nz100.(~$us60)

[geo_allino]

hey THANKS GUYS.

I guess the next thing I am gonna do is gonna change the oil, and later when I get back to Phoexnix, I am gonna check into changing the oil pump as so many of you have suggested.

FIRST OF ALL I WANT TO THANK YOU ALL FOR GIVING ME SO MUCH GOOD INFOMATION. I TRUELY APPRECIATE IT.

Is it hard to change those oil pump?

Thanks!!

[maigret]

To replace one of the easiest I have done. The pump is external on this motor. Remove the carbs and there it is on the back of the distributor.