Scenic 1.5 dCi Engine Rebuild.

[steelcityuk]

Hi All.

Work started some time ago on my latest project. The car was bought with a no start fault, it was easy to start with a bump. I drove the car about 180 miles to home without too much trouble, sure if you tried to accelerate at anything more than a steady pace error messages came up on the dash but it did manage 70mpg at just under 70mph. That was why I wanted one.

A leak off test show two injectors were faulty, one was leaking back an incredible amount. Two replacement injectors had the car starting on the button. I gave the car a general service plus cambelt and water pump. However the engine wasn't right. I was concerned with the amount of oil in the inlet tract and the poor performance. Occasionally error messages popped up. The decision was made to pull out the engine and rebuild it. It has over 201,000 on the clock...

More proof if it's needed that EGR systems coat everything in soot, some sticky some hard depending on where it's deposited. I'll clean this up with spray oven cleaner and brake/carb cleaner.


I didn't take a photo of the pipe that goes into this but it was about 50% blocked with sticky soot.


After removing the front end, radiators, driveshafts, etc. it's pretty easy to get the engine out with gearbox attached.


From the front.


From the rear.


After stripping off a few parts a clean up with spray oven cleaner she looks like this.


To be continued.

Steve.

[bxzx16v]

What's your opinion on the 1.5dci Steve? I maybe looking at something with the 1.5Dci fitted but I've heard mixed reviews.

Thanks, Mark

[Northern_Mike]

I was a passenger in a Nissan NV200 fitted with this 1.5 engine last week for 300 miles at 80-95mph. It was quiet and amazingly returned 44mpg despite being hammered.

Sent from my GT-I9300 using Tapatalk

[evilally]

Great to see some Renault loving round here for once What particular 1.5 is it, any plans for some upgrades while it's out? They do seem capable of almost freakishly good MPG.

[steelcityuk]

Hi,

The engine is a K9K 728 so it's rated at just over 100 bhp. Wikipedia mistakenly lists it as 80 odd bhp. Compared to the lower output versions the higher output types have strengthened internals and variable geometry turbos.

I haven't really had much time to build up an impression of the 1.5 to be honest, at least not in the running of one. Design wise it seems quirky but maybe that's because I'm used to more traditional diesels. By quirky I mean -

The fuel pump is timed to the engine despite it being a common rail design.
The crankshaft sprocket isn't keyed to the crankshaft so if the sprocket/crank nose isn't grease free and the bolt tightened correctly the timing can slip - I much prefer a vernier pulley but this increases cost and weight.
There's no locking pin position on the flywheel, it's a sized length peg that a crank web rests against whilst tightening the sprocket bolt.
The inlet plenum is cast as part of the cylinder head this makes it difficult to clean out effectively and impossible to grind and polish the inlet ports.
The fuel filter seems overly elaborate with prices to match.

Maybe the key to running a 1.5 successfully is to use only oil that meets the highest spec changed twice a year - changed late Autumn and early Spring, always put a good oil flush in it before changing the oil and blocking off the EGR to stop gunk build up in the intake system and combustion chambers.

As noted it's hard to see what can be done to improved the efficiency of the engine due to cylinder head design. However I intend to polish the piston tops and chambers to reject as much heat as possible and hopefully keep them cleaner longer. The same treatment will be given to the valve heads. It would be possible to drill a couple of holes through the cat honeycomb to reduce back pressure which should improve spool up of the turbo but some tuners think this can lead to boost spikes. A remap is probably the best bet to improve performance.

Steve.

[steelcityuk]

After a quick clean up I removed the gearbox so that I could check the clutch and flywheel. I was expecting the worse, a dual mass flywheel that needed replacement, that would add about another £300 to the cost of the rebuild. To my surprise it doesn't have one.

The state of the Concentric Slave Cylinder wasn't good, the gaiter had split away from the bearing and the whole thing looked rusty. The friction plate is nearly down to the rivets and will have to be replaced along with the slave cylinder. The flywheel is in good condition with no signs of overheating. The housing needs a thorough cleaning.


I 've read on other forums that the pistons rings on these engines are prone to gumming up and sticking. It seemed a good idea to remove the pistons to check for this. Sure enough there was extensive hard carbon build up in the piston ring grooves and on the piston side above the top ring, the oil scraper rings were coated in a very gummy oil/carbon gunk.There's various reports of the shells rotating in their housings leading to crank damage which was a real worry, thankfully none of the bearings have slipped and the crank appears in good condition. The big end shells are showing copper through their white metal and will be replaced.

[bxzx16v]

Thanks Steve, I'll keep an eye on this thread, I've driven a couple of cars with this engine fitted, one a Renault modus with 106 bhp which was very impressive and the other a Dacia duster which I was very happy with.

Mark

[demag]

I had a Grand Scenic fitted with one of these. Electronically the car was a pile of doggy poo but the engine was quiet and very economical. 60mpg was possible on the motorway and 40-50mpg round town. I got rid because of electronic problems but mechanically it was sound. It was a big old bus as well with 7 seats so can't grumble about the engine.

[lexi]

Very interesting. What reg year is the car Steve? It seems about 200 k is about rebuild time on a lot of these?
They are probably more susceptible to less than perfect servicing. It is small block working and revving hard.

The Renault range has great designs for many uses. If you get a good one though, because there are many problems. Probably why they pile them high and sell them cheap. There are masses of them around too which obviously means more problems reported. Somebody has had good use from that one Steve?

[steelcityuk]

The car is an 05 reg and appears to have been looked after pretty well. It's had full main dealer servicing but I think it's mileage is showing mechanically. One pinch bolt sheared on the right strut/hub and the other side took a fair bit of heat and patience to remove, it needs a new lower ball joint so a pair will probably be fitted. The brakes are very sharp, there's no rust on her anywhere and the interior is in good condition so I think you're right, someone's had their moneys worth.

Steve.

[steelcityuk]

As part of the rebuild I've decided to spend time cleaning up and painting the alloy parts. It should help keep corrosion at bay and makes keeping the engine clean easier, plus I find it makes spotting leaks easier.

On the XM I used special metals primer followed by Hammerite which worked well but as luck would have it JTF had a large tin of Copper coloured Hammerite Straight to Galvanised metal going cheap. This doesn't need a primer coat so that's a bonus.

Cooker hoods aren't just for cooking under and refinishing leather steering wheels. This is the first coat.


Cleaning the head up took ages, the amount of hard soot and sticky carbon was surprising. It took over 4 tins of oven cleaner to shift it all. A quick sand blast removed the corrosion before a quick clean up so that it could be painted. Once the paint's fully hardened it'll get a thorough cleaning to remove any sand particles that got through the 'shielding'.


I've bought a couple of micrometers so that I can check the dimensions of the crank journals and the valve buckets. I need to carefully read the Renault documentation again regarding main bearing sizes, I'm sure that different sizes exist depending on the cranks finished size. A look at the Haynes book will hopefully clear up what sounds to be a very strange idea

Steve.

[lexi]

It is looking like the old Leyland Gold Seal engines. I have found standard hammerite smooth to be very heat resistant. Maybe that stuff will be good too. The crankshaft bearing thing? Is that why there are some issues with spun bearings I wonder?

[steelcityuk]

Yeah I did think about the BL engines when I bought the stuff but at £2.99 for a litre I didn't think it mattered that much.

Don't know about the spun bearing thing, there are no locating tabs on the shells so either you have to be careful fitting them or use the correct tool/jig. Haynes only mention the usual three sizes, std, 0.25 and 0.50 or something along those lines.

Here's a taster of what I've read -

Note:
The hole (1) defines the diameter category of the crankshaft bearings on the cylinder block. It is only possible to have one diameter category of crankshaft bearings on one engine.

Measure the dimension (2) to identify the diameter category of the crankshaft bearings on the cylinder block.
(2) =33 mm : - the diameter category is 1.- the diameter of the crankshaft bearings on the cylinder block is 51.936 to 51.942 mm excl. .
(2) =43 mm : - the diameter category is 2 ,- the diameter of the crankshaft bearings on the cylinder block is51.942 incl. to 51.949 mm .

The crank has markings too -

(1) diameter category of journal no.1, flywheel end,
(2) diameter category of journal no.5, timing end,
(3) line indicating the diameter class of the journals,
(4) line indicating the diameter class of the crankpins

The marks of journal categoryA, G, K, R,W correspond to a diameter of47.990 to 47.997 mm excl. ,
The marks of journal categoryB, H, L, S, Y correspond to a diameter of47.997 incl. to 48.003 mm excl. ,
The marks of journal categoryC, J, O, T, Z correspond to a diameter of48.003 incl. to 48.010 mm excl.

>>

So I need to be careful that I understand what Renault means.

Steve.

[lexi]

Yes indeed. Lots of measuring twice and cutting once kind of thing. Will be a great little tool that car once sorted.

[steelcityuk]

Tonight I removed the main bearing caps to check for wear of the shells and measure journal diameter.

I found this. Fortunately the crank is undamaged. Definately needs new main bearings.


The gearbox got painted the other night but it was so cold I had to keep the paint warm in a bowl of water.


The block's has had a couple of coats of Hammerite and looks much better.




I'm now waiting for parts.

Steve.