Replacement engine

[alexperkins]

You are correct. I got a bit muddled on lack of sleep. 5W40 is thinner when cooler for an easier start

If it's a 16V it's removal of belts. On 8/12V you can take it off without

[littlepolo]

It is a 16V, unfortunately in this case.

So why would full synthetic 5W 40 oil (Fuchs) not quieten things down as much as the 10W 40 semi (Castrol) when the engine is hot?

[alexperkins]

Different blend.

Synthetic is notoriously thinner than semi-synthetic when hot. Its to do with how the molecules react to heat. I wont go into the science as its very boring, but semi or mineral is always thicker and quieter.

[RUM4MO]

My suggestion on keeping the oil separator from drying out was easier to give than say exactly how to achieve that, maybe wash the separator out with petrol a few times, which will dry it out, then tip some clean engine oil into every opening and try to make sure that it gets every where!

Material for water pump impellor, I suppose that you are aware that this was up for lots of discussion in the early days of that model of Polo - VW Group were getting a bad name for using an unsuitable plastic that tended to crack with age and allow the pump spindle to turn without turning the impellor! Hence the old advise to avoid fitting VW Group sourced pumps, I think that with time VW Group sorted things out, certainly my second pump, I sourced it from VW garage as an exchange item, had a metal impellor, but maybe the next VW sourced one was back to plastic.

Edit:- there are two O-ring seals on the separator, I still have five of the bigger ones which was a mistake with the SEAT part's guy when I ordered one for the late 2009 Ibiza 1.4 16V - at that point in time, VW Group were getting a bad name for suddenly changing O-ring suppliers and quite a few 2008/2009 1.4 16V engines had an oil leak from maybe the big O-ring seal, which was changed from a black material to a grey material!

[littlepolo]

The old Polo engine has been holding out and I've been putting off the swap due to lack of enthusiasm. However I now need to get it done and wanted to check on something I had not considered before. How would the immobilizer be affected by an engine swap? There are various sensors on the engine, such as crank and cam position. Are any of those coded to the original ECU/engine? I plan to swap the BBY engine for another BBY engine, retaining the original ECU. I'd prefer not to swap the above sensors unless absolutely necessary.

[alexperkins]

No they are just sensors. It’s only codeable modules that you have to worry about

Immobiliser is paired to the ECU and clocks

So long as you touch neither it’s all good

[RUM4MO]

Good luck, I find that when the weather gets colder my enthusiasm drops through the floor, I've only got some garage clearing out of "definitely not needed" stuff to do - and even that does not sound like a good job when the temperature is almost zero! Still I must be brave, maybe!

[littlepolo]

No they are just sensors. It’s only codeable modules that you have to worry about

Immobiliser is paired to the ECU and clocks

So long as you touch neither it’s all good

Thanks. I guess I have no further excuses now.

[littlepolo]

I spent most of last week working on the engine after firstly removing the sump to check for any debris. It was a pain as described in another thread. Basically, undoing the driveshaft and jacking up the engine (off mount) helps to create space to work. I used a cut down allen key with a tube on the sump bolts in that vicinity.

Whilst the sump was off I inspected and replaced the oil pump. There was some metal filings on the magnetic drain plug and it looked like some debris had gone through the pump and left the surfaces slightly pitted. Put a new gasket on the oil pump pickup (which was clean) and the oil pump to block surface. I decided to retain the original block (now 90K mls) which I had originally intended to replace as it looked good enough.

Removed the cam carrier and found a nice H profile on the cam lobes. I think this explains most of the noise. One of the hydraulic tappets had disintegrated and the rockers, etc. were not in good condition. There was varnish on the cam carrier indicating it had not had regular oil changes (this was part of a head/cam assy swapped by a back street garage when I got into a tight spot last year). The whole assembly was scrap. The floor of the cam carrier looked like a metalwork shop and I'm surprised more debris was not circulated (I guess the poor oil pressure/flow was a factor).

It's possible the back street garage had also reused head bolts because one was burred on the splines and I could not get enough drive to undo it and had to drill it off. It drilled out quite easily (head only) using a good coated drill. Similarly, the head was badly varnished indicating poor maintenance but could just about be classed as serviceable.

I removed the head and cam carrier from the donor engine (1.4 BBY from a Seat) and found it to be in very good condition which is what you might expect with only 25K mls. The oil pump I used above came from this engine. Purchased new head bolts, gaskets, belts, etc. and proceeded to build the top end. All fairly straightforward and according to the book. I just about remembered where the hoses went but managed to split the crankcase oil breather which runs from the rear of the engine to the inlet manifold. Incidentally the inlet manifold and injector rail from the donor engine are not the same.

Incidentally, I removed the injector rail leaving the hoses attached and just put it to one side. I had seen a video of someone who disconnected the fuel hoses and had problems with fuel pumping out during the work so wanted to avoid this risk. I did buy new o rings for the injectors and fitted them before replacing the rail. I cleaned the throttle body, plate, EGR, etc. and used new gaskets on refitting.

I purchased a tool to lock the cams which goes through the cam sprockets and then lock into the cam carrier itself. Previously I made up a tool using bolts but wanted to be absolutely sure this time after doing all this work. The belts are never easy to fit but managed to get them on OK. I marked the pulleys, TDC, etc. with Tippex to ensure everything was and remained aligned. There was a slight movement after fitting the new belts but well under a tooth. Rotated the engine a few times by hand and everything looked OK.

Torqued up the remaining bolts (crankshaft, etc.), fitted plugs, leads, etc. I noticed the old MAF sensor seemed to have no sensor wire in it (the ones I have seen mainly have a wire with a bulb but this one seems only to have a foil like plate deep in the housing). I had a new part in the shed so fitted that. Fitted a new thermostat (old metal type) reconnected hoses and refilled with the coolant I had drained out earlier.

I was aware that a throttle body adaptation was likely needed but did not have a cable or software to hand. While waiting for delivery I decided to start the engine and was amazed when it started on the first crank. Engine seemed to be in a fast idle and running a little lumpy. After a short time the EPC light came on and it was not possible to increase revs by the throttle.

Codes 17961 and 17912 appeared. I interpreted these with some hope that a TBA would resolve them. Then I realized I had left off the cam breather (non-return valve) and thought this might cause the signal due to a leak. Refitted the part but the same codes appeared. I became a bit concerned on one very cold morning when a lot of condensation came out of the exhaust and convinced myself it was running rich and clearing condensation from the exhaust system due to having sat for over a week. The engine temp came up and after some time started to creep over normal so I shut the engine off. All the anti-freeze that had come out had not gone back in and appeared not to be circulating. This made me wonder of the (new) thermostat and/or (old) thermostat housing is OK. I have heard that the plastic housing distorts and stops the thermostat from opening. The coolant pump was refitted but it is under a year old and looked absolutely fine. Of course, it could be an airlock so maybe worth draining and refilling?

The cable and software arrived and so I installed the software on my laptop and tried to do a TBA. It seemed to work at first but then showed ERROR. After some investigation the ambient temp (3C) was below the 5C needed to run the adaptation. I started the engine and ran it for a few minutes and retried. TBA ran OK (was expecting to hear some whirring but there was none). Checked codes and there were none.

Went to start the engine and it fired but did not run. Cranked it over several times but no go. This was puzzling because it had run reasonably well, albeit slightly erratic, before. Removed plugs and found they were a bit wet. Decided to revert back to original plugs so fitted them. Then I realized I had also changed the MAF sensor so unplugged it to see if that made any difference. Engine started first time. Now showing 16497 and 17564 (no other codes).

I strongly suspect the original MAF sensor (with no wire) is defective and plan to order a new one. I have no idea what brand the old one or the new one are - they seem to be a pattern part. Not sure what brand is fitted by VAG. Will a Hella MAF be OK? Only other part I might need is a new thermostat housing but I'll firstly try draining and refilling in case there is an airlock.

Where this all started was with noisy tappets. I inspected the tappets from the donor engine and with such low miles thought they should be OK. I poured oil during reassembly and used Graphogen on the cams. Bottom end has 90K and top end 25K. I'm currently using Shell Helix 5W 30 oil and thinking to change to Quantum or Fuchs 5W 40 after the oil now in the engine has flushed and cleaned.

The tappet noise itself now sounds very normal for a VW Polo and I hope it will settle down even more after I get some miles on it.

[RUM4MO]

Good enough so far, almost there then! That is a MAP sensor not a MAF sensor, if it is faulty it should log "barometric/manifold pressure signal" issues, I think. I removed the one from my wife's Polo and cleaned it and then swopped it for an older version and just left that in, and yes there was a small bulb in there I think. Pierberg were the factory suppliers for that part. If I can find my notes from when we had that car, I'll let you know the part number and version, maybe I'll look out the original one if it is still in the garage.
.
Edit:- I was wrong there, the MAP sensor is made by Magneti Marelli and is type T - PRT04/B this is also called a Thrust Sensor by VW Group and its part number is 036 906 051. I replaced that original one with a used one which was an earlier version, ie T - PRT04

[littlepolo]

Thanks, it is of course a MAP sensor not MAF. There is a foil plate type but I think they were not fitted to Polos and the foil would have to be in the airstream. The old MAP has the foil at the bottom of the "tube" so I think the wires have broken off (or it's been bodged).

There is a Bosch MAP with a part number ending in 4, indicating "approved aftermarket part" (I think the original part no ended in 5), but I've read some people had problems with them (on other cars). There are no fault codes (except when I unplug the MAP), however with the new MAP (eBay part) the car won't start and run (it fires but won't run). So I'm running with the MAP unplugged at the moment - will that cause any problems?

A part number for the original part and recommendations for any good third party unit will be helpful. I would expect VDO and Hella to be OK but have no experience with them and it could be another gamble.

[littlepolo]

Just in case anyone can add anything more to help today I started up the Polo with the expansion chamber cover off. As it warmed up I squeezed the hoses and saw the fluid in the reservoir rise and fall a little. The temp eventually came up to normal (90) which is middle of the dial and stayed there.

I ran the engine between a fast idle up to 2500 rpm. When it warmed up the idle dropped to around 650 rpm and was lumpy. When I increased revs it was a little better and then above 1800/2000 rpm appeared to run as normal. Foot of the pedal and it dropped back to a low lumpy idle. No particular smells or anything unusual coming out of the exhaust. The MAP sensor is still unplugged.

After a while the temp started to creep above normal (about half way to the next marker) so I switched off again. It stayed at normal temp longer that it did the other day. Does air in the system still seem likely? I could not get the heater to work at all but that could be the ongoing problem with the flap motor which I need to tackle next.

Do the above idle symptoms suggest it is the MAP sensor?

[RUM4MO]

I think that I've read, in the past, that some system sensors do need to be from a specific manufacturer in order to work okay for an extended period of use, you would think that that is crazy/wrong, but in some cases it seems to be correct. By the way, the earlier version of that part number that I fitted to that car seemed to work okay for the remainder of the time we owned it, maybe a couple of years, the original MAP sensor was also okay though I was trying to get to the bottom of another engine issue without disregarding any possibility.

When you remove the lead to a sensor, the car's system should be able to use some default values to enable the car to run and probably make more use of other sensor data. What seems to have been happening with your "other non VAG" sensor is that it s giving out valid data but completely bad data that is giving that car problems.

Why not give up with the you have and gamble on buying the one on ebay right now for £10 +p&p as it is a genuine Magneti Marelli T-PRT04/B which is exactly what would have been fitted to that car at the factory?

[RUM4MO]

I have never ever drained that engine type of water, but I do know that its younger version is a pig to get air out of, and I have had personal experience of that, mainly showing up as hot air > cold air > hot air, that went on for about 10 miles or so. So, I turned to the wonderful world of the internet and discovered the best or only way to get air out of that system is to, with a large jug of prepared coolant, remove the ECT sensor and pour more coolant in until the coolant escaping from that sensor hole runs clear of bubbles, then while still pouring coolant in, refit that sensor. Sounds a bit of a faff but it worked first time!

Edit:- https://www.ebay.co.uk/itm/2003-VW-AUDI ... 0005.m1851

[littlepolo]

I've taken a punt on the used Magnetti Marelli sensor on eBay.