Hi, 

My skoda fabia sedan 2006 1.4 16 valve with BKY engine type needed a new engine and the only good use engine I could get is the AHW type.

 

I have completed the swap and a few things that was different that I had to remove from my old engine which includes the engine knock sensor (AHW has a different connector). The Oil trap crankcase breather /Valve engine block breather is different, I used the one from the BKY engine has it has an electrical connection while the AHW does have one. See image below:

BKY

 

AHW. 

 

 

The EGR of the engine was already deleted using the delete kit. 

 

The last difference which is my main concern is the valve engine block breather pipe located on the top of the BKY engine which is not present in the AHW engine.

 

 

Image of the BKY with breather pipe. 

 

Image of AHW without breather pipe. 

 

The engine started at the second attempt with smooth idle at around 600 - 700 RPM. My concern is that with the part switch from BKY engine to the AHW engine with out the top cylinder breather pipe, hope the engine won't be building up pressure and cause damage to the pistons. 

 

One other thing I had to swap was the engine hanger and complete cover for the timing chain. 

 

I will appreciate if any can help. Thanks. 

The valve on the cam cover of the BKY is an air inlet, so you're more likely to have too much vacuum in the crankcase than too much pressure. But that would depend on where the outlet of the breather module is routed to. I guess you've put the intake manifold from the BKY on the AHW? So the breather output goes in on the vacuum side of the throttle?

 

Probably easiest to swap to the AHW breather module and route its output to the air filter side of the throttle body.

Thanks for the quick reply. 

 

Yes you are right, I forgot to mention that I had to use the intake manifold and throttle body from the BKY engine. The breather out goes to the manifold just as it was on the BKY engine.

 

If I get you right, I need to make use of the AHW breather module instead and find a way to route it to the air filter side and easiest I believe is to make use of the point where the top cylinder valve engine breather is connected to. 

 

If I am able to find the parts to do that (I will need to find another breather module as the one that came with the AHW engine is broken and might be difficult getting it here in Nigeria), what happens to the point where it was formally connected to on the intake manifold? Do I block it, as leaving it open will cause rough idle and noise (provide it idles). Also the electricity connection will be left unconnected. 

 

 

Just in case I can't find a fix and leave it the way it is, what happens? 

 

 

P.S I am not an expert, I just learn to fix my car.

Yes, you would need to block the port on the intake manifold if you did use the AHW breather module.

The electrical connection to the BKY breather module is a heater, to prevent water from crankcase vapours freezing in there, Not a big risk in Nigeria I think.

 

If you leave it as it is, I don't know what will happen. You may get seals failing due to the pressure difference between crankcase and atmosphere. (Crankcase pressure lower than it is designed to be). Maybe it won't be any problem?

 

Another possible work-around is to make a suitable hole for the air entry valve in the AHW cam cover. This would need some care and thought, and probably requires the cam cover to be off the engine.  This would be. better, because it would behave more like the BKY system, and this is what the engine ECU will be expecting in terms of interaction between inlet manifold pressures and the breather system. 

 

 

It isn't critical as long as the block is vented into the intake somewhere, elaborate PCV strategies are designed to minimise parasitic losses and reduce fuel consumption and emissions, it doesn't really matter if it's not working as designed as long as it's accomplishing it's basic function of protecting the engine from strong vacuum or high pressure conditions.

1 hour ago, sepulchrave said:

protecting the engine from strong vacuum

That might be what happens though at idle, without any air entry, depending on blow-by level I suppose.

 

I wonder if that breather valve would fit in/on the dipstick tube, instead of the dipstick?  Or into a modified oil filler cap?