My 1990 V6 Sei is finally back on the road

[dcz1643]

Update, properly installed the AIC valve, with clips. The car is still running badly. I will build a blink code reader and see what I get. Cheers

[dcz1643]

Hi All, my XM is now running well. To fix it I changed the AIC Valve, which didn’t do anything. I then systematically went through all of the engine bay wiring, including removing the 3 control/computer units, as there was some signs of oxidation in the compartment. Fortunately, when I opened up each of the Bosch units, they were clean and corrosion free inside. I cleaned every connector under the bonnet with isopropyl alcohol, mild abrasive paper (only on a couple of connectors) and gave them a liberal squirt of Servisol before putting them back together. I had already removed the troublesome earth connectors years ago but I took every earth off and cleaned them too. Today, she started on the button, idled great and when I took her for a drive, she was smooth and powerful. We took out 2 mouse nests from under the bonnet a few years ago but whilst I was doing the electrics, I found another one under the inlet manifold, in the V of the engine, complete with a cute mummified field mouse, that has now been cleaned out. I think I am lucky with the wiring, as except for one multi plug, they seemed to have taken a fancy to the cloth binding in the loom and haven’t chewed the plastic insulation. I am renewing the cloth binding and I have the chewed plug to sort out. All in all, I am pleased the engine is running properly again and I can get on with things. Also, I am in the process of making a blink code indicator and if anyone needs one, I can make some additional ones. Picture attached. Cheers

[Dieselman]

Good news on the fix front, just need to wear some rubber off those tyres now. I ensure I now grease all connectors to stop corrosion.

That plug looks like the seven pin, Hydractive, electrovalve and sensors plug by the Rh sphere. Obviously it needs repairing, but won't have any effect on the engine running.

That's a fancy Blink Code reader, where did you obtain that? I'm assuming that isn't one you have just made.

[dcz1643]

Hi, good news indeed, there is some service work to be done. The coolant needs draining and the engine needs flushing, the current coolant is a little on the rusty side. I will give the engine a service and change the fuel filter but I will put it into the Citroen specialist up here, for a gearbox service. I made the fancy blink code reader, I used to be a Design & Technology teacher and when I retired, I put together a small workshop.as well as some woodworking machines, I have a CNC router and a laser cutter/engraver. So it looks flasher (pardon the pun) than it really is. You are right, I need to burn some rubber of the tyres now. Cheers

[Dieselman]

With the skills you have looking after your XM will be a rewarding challenge.
Assuming you have a pair of ramps, I would do the ATF change yourself, it's really easy on the 4HP-18.
Run the car onto ramps, remove the drain plug and filter,
While it drains clean the filter and change the two O rings,
refit filter and drain plug, add 3 litres of ATF via the dipstick tube.
set car level, warm up to full operating temperature, run through all the gear selections, check ATF level at 80c markings. Add ATF as required.

[dcz1643]

Hi, thanks for this. I don’t have ramps but I do have a trolly jack and axle stands, which I usually use for under-car work. I recently changed the rear air shocks on my Explorer using them. Do you have any advice on underbody protection? It’s not too bad under there but there are some surface rust areas that I will need to clean and treat but what would you use to prevent future corrosion? I used waxoil on my 1974 Spitfire but I was wondering if there is anything you would recommend. Cheers

[Dieselman]

I normally just wire wheel, treat and paint, adding underbody sealant/schutz for high impact areas and cavity wax in any cavities.

If you can stop a Triumph spitfire rusting, an XM shouldn't present an issue. The cavities are where rot happens.

Here is a post referencing gearbox ATF change for a 4HP-18. The O ring and copper washer sizes are given in it. viewtopic.php?p=132553#p132553

[dcz1643]

I am now servicing the engine and cooling system on the V6. I have a couple of questions people maybe able to help me with. Firstly, some how the dipstick top has broken off and gone missing, so ideally I would like to replace it but I haven’t found one yet and suspect, as usual, one will be hard to find, so if anyone can help, that would be great. I have changed the oil and the quantity published is 6L or 6.5L. As I understand it, Citroen issued a bulletin (XM1 No 40) in 1991 reducing the recommended capacity to 6L. I put 6L in, do people agree that is the correct amount for my V6?. Secondly, the coolant was quite rusty, so I have attempted to flush the whole system, with some success. However I could not find any drain points for the system and the bottom hose uses the original circlip type fasteners and I found it impossible to open the clip and get it off. Does anyone have any suggestions regarding draining and flushing the system? Finally, I have fitted silicone hoses to my 1974 spitfire, which I think are fantastic. Does anyone know of a company that supplies a full set of silicone hoses for my V6 PVR engine? Thanks again for all of the help and support, particularly Dieselman.

[Dieselman]

Why Me, come on Guys, chip in.

There are no aftermarket hoses for Xm cooling systems.
If the radiator is the original it should have a drain bib at the lower right corner. Unclipping those hose clamps without the proper tool is a challenge, especially that lower one. A remote tool is the only way to access that clamp, it's a bit tight for space down there. See: https://www.ebay.co.uk/itm/204413734042 ... terest_ms=
There should be a drain cock on the rear side of the engine block.

Dipsticks
As this is a common issue We have a thread running about this and a chart that should be useful. See linked post with latest sheet. viewtopic.php?p=130668#p130668


From memory, the distance to the bend of the dipstick to the top of the dipstick tube is 23mm. I would need to check on my Prv engines to be sure, as that might be the figure for the 2.1Td.
Make a mark and add a length of tube to act as the correct length space and the dipstick will function as intended.
I too am unsure whether to lower the oil quantity as although the sump did change I can't see it reduced volume and the dipstick tube stayed the same length.
There are two schools of thought regarding oil level.
1: the higher oil level was contributing to leaks, oil burning, and maybe oil frothing.
2: a greater quantity of oil is beneficial for cooling and oil life.

Given your car was run for years at the original fill volume, I think that will be correct.

Synthetic wine bottle corks make good dipstick knobs, however Meca Place make replacement dipstick tops in plastic. See https://mecaplace.com/produit/kit-pour- ... oteur-prv/

[dcz1643]

Thank you for your reply, as usual it is very helpful. Regarding the drain plug on the radiator, is this what you mean? If it is, i did unscrew this and nothing came out. So if it is the drain plug, the radiator must be blocked?