Thread: Why do 2.7 cranks break?

Exploded oil cooler

The clean passages are oil and the black passages are coolant which may explain the same slimy grunge I was getting in the reservoir bottle! A series of very flat old and hard rubber seals keeps everything separated.

Fuel cooler module at bottom the coolant passes pretty much straight through.



Here’s the holes related to pictures above. Blue coolant and green oil. The coolant flow may be back the front but doesn’t matter here.

So focusing on the C valve which can only open one way the oil enters the housing and then dips into the cooler part before popping up under the NRV to enter the filter housing. The oil is therefore cooled after the sump before the filter by my logic.

B is straight out as is A via the previously marked holes.



Here’s the NRV spring close up.

Certainly going above and beyond there! So we now know the oil is cooled pre-filter and the assembly has anti-drainback built in. 2 things we didn't know earlier.

What's the chances the bypass valve is in the top of the cap and forms part of the spring assembly that keeps the filter seated? If it wasn't there there'd be no need for the top of the filter element to have a hole in it.

Now if only that was in the manual.

This is excellent - so between the NRV, o-rings, plastic centre piece, bypass and gasket there is plenty of parts to fail in this lovely part.

Time to start planning to change out the oil cooler and filter assembly.

Originally Posted by DiscoDB

Now if only that was in the manual.

This is excellent - so between the NRV, o-rings, plastic centre piece, bypass and gasket there is plenty of parts to fail in this lovely part.

Time to start planning to change out the oil cooler and filter assembly.

It’s all making a lot more sense at least. Yes, replace that cooler, I’d almost put it in the 7 year timing belt category.

I might change my oil cooler too after seeing all this...on the subject of replacement coolers, what's the consensus of using genuine vs. Nissens brand? I know genuine is usually better but at £300 vs £100 the Nissens is pretty tempting.

Originally Posted by BradC

If you consider putting unfiltered oil into the gallerys I suppose. Plenty of mechanics refuse to pre-fill a filter due to the risk of contamination.

So now we have established the flow direction, going back to Oval Auto’s filling the oil gallery’s with new oil.

Brad is correct in that you normally shouldn’t introduce unfiltered oil after the oil filter. All it would take is a small contaminate to end up in say the Turbo bearing and you are up for an expensive rebuild.

Ideally you would pre-filter the new oil and then transfer the oil into an oil safe container.

It is possible they have pre-filtered the oil, but they are using an open and used oil jug to pour the oil.

If I was running an engine rebuild workshop, I would buy (or even make up) a filter cart with a pump to pre-filter the oil and pump into the gallery.

Originally Posted by DiscoDB

So now we have established the flow direction, going back to Oval Auto’s filling the oil gallery’s with new oil.

Brad is correct in that you normally shouldn’t introduce unfiltered oil after the oil filter. All it would take is a small contaminate to end up in say the Turbo bearing and you are up for an expensive rebuild.

Ideally you would pre-filter the new oil and then transfer the oil into an oil safe container.

It is possible they have pre-filtered the oil, but they are using an open and used oil jug to pour the oil.

If I was running an engine rebuild workshop, I would buy (or even make up) a filter cart with a pump to pre-filter the oil and pump into the gallery.

The centre of the spear is the feed to the bearings. Inside the filter. The oil is being forced through the filter into the centre cavity.

On the 2.7 this is only open on the top so this is the height of oil retained in the filter housing with engine off.

If I was filling from a new oil container I’d never think contaminants could be present.

I’ve tested new containers of oil and you’d be surprised!

Stop over analysing the task.

Remove filter, drain sump.
Lubricate oring on new filter and then place into housing and clip in - doesn’t need visibility just gently rotate until you can feel it find the correct location and then push home.
Fit new seal to cover, lubricate with new oil and Screw cover on.
By now sump is well and truly drained so fit plug.
Fill engine with oil - I measure mine out and shy by 100ml.

I then start up and run for a minute before shutting down and waiting a flow back interval (2.7) and then check dipstick.

Top off to suit and job done.