75 P6 Engine Tick After Warming Up

M

mick88

New Member
Good morning gurus,

Looking for a bit of help running diagnostics on a tapping sound coming from my P6 Engine bay.

It only ever happens after the car is warm, both during idle and under load, the tap just speeds up or slows down.

After a bit of reasesrch I've found it could be the tappets, or a leaky exhaust manifold, or something else I haven't heard of.

Is anyone out there able to suggest the best diagnostics to run in order to find the source? It sounds like it's coming mostly from the right side of the Engine bay as you look at it.

Attached video is the car and sound in question.

Thanks in advance,

Mick

 
Seized lifter I would think but lifting the tappet cover will be a lot more revealing
 
Good morning all,

After getting back from interstate I've finally got the blue beast in the shed for a look around.

So the source of the noise definately looks like it's coming from the right side, and have noticed oil leaking into the manifold.

Thinking it might be the valve gasket I bought a top end gasket set. May have been a bit of overkill, but while I was in there I thought I'd loosen the manifold and have a look.

Turns out there aren't any gaskets on the manifold. Could this be the source of the problem?

I'm a real slow worker as this is the first car I've ever touched, but hopefully over the weekend I can get it all done and back on the road for a test.

Pictures attached for your pleasure.

Mick

Rover P6 missing gaskets
 
Yea there certainly is a lot of 'patina' under the hood.
I'm just realising how fiddly this damn job is
 
The standard P6 has no gaskets between head and exhaust manifold. You may find some threads here about it. I followed Harveys advice, not to use later SD1 gaskets, just take care everything is clean (and not cracked...) and use some grease on the surfaces. It works perfect. Be careful tightening the bolts and use a some copper paste. I did not reuse the safety clamps, simply used plain washers and stop washers (do not know how you guys call it, the washers with the split open ends).
 
Thanks again for all the replies here.
Another weekend of farting around under the hood and I've noticed the two rods attached to the springy looking things (showing my knowledge here!) aren't rotating like the rest.
Do these go down to the lifters? And is that a sign that they might be seized?
I've also read that cleaning all the gunk out might not be the best idea, but it's so tempting to get at it all.
Thanks again
 
You mean, two pushrods (from 16) feel like sticking ? The valves for this (these) cyclinders were closed when you tested it ? Looking at the beginning of your thread the pros tips went for a seized lifter (damn, my English is complicated this morning). Looking at your really dirty cyl heads (no, you cannot clean them without taking the heads off !!!!), you should dive deeper, means check the lifters at the bottom end of the pushrods. But, that means taking off the inlet manifold (you already have a top end gasket set :)). Loosening the shaft units (with the rockers) in your head, you can take out the rods (check if still straight or bended) and then TRY to take out carefully the lifters. Carefully means it should be prevented to damage the bore where the lifter/tappet) goes in. On the visual condition of your heads you normally should start a full top-end rebuild, but if you say, I want to drive now this summer and start work somewhere after the season, take out the two lifters you mean, check them and if scored, polish them with sanding paper starting with 800-1000 grade to 2000 with some oil. It´s a simple repair and some here will say, not professional, but it seems that your engine is not far away from further work anyway. The perfect thing on the Rover, parts are really not expensive.
Then, for "cleaning", do nothing except oil (+filter) change and take off the engine sump cleaning this one and the pick-up strainer. With automatic car you must loosen the two downpipes (soak each 3 bolts/nuts with WD 40 before and when loosening still apply WD40).
 
Not sure how to see whether the valves were open when I tested it, but the springs were moving up and down so I guess no?? The pushrods were also moving up and down, just not rotating like the rest.

I think I'm going to tackle taking the inlet off, as well as the heads, and give the heads a good clean out while they're off. Do the valves need to be removed for this as well? I'd like to avoid this if possible.
Last time it ran I also noticed smoke coming from the dip stick tube. A quick search suggested piston rings?? But I'll tackle that when I dive deeper.

Also, just to satisfy my curiosity, why does the ticking only come when the car is warm? Trying to understand as much about his as possible.

I'll continue to update here with my fumbling attempts at mechanics with plenty of photos and videos, but I'm really having a blast learning something new.

Thanks again to all the gurus here offering invaluable help and advice. I think I'm beginning to understand this beast very slowly :)
 
Hi Mick,

Might I suggest that you take the heads to an engine workshop and allow them to refurbish your heads. I did this with my Rover's original heads 20 years ago. They checked the springs, all were found to be within spec, but two exhaust valves were found to be burnt, so these needed attention. They came back looking like new :) They can also check the valve seats and guides and service as necessary.

Smoke coming from the dip stick is blow by, so that does indeed suggest rings. The ticking likely appears once the engine is warm as the clearances will increase with temperature.

Ron.
 
With a possible blow-by you should carry out a compression test first. It´s not a big job, so no big money spent but necessary to decide how to go on. Take off the heads only makes no sense, if the bottom of the engine needs attention too. For heads you can save some money when you dismantle everything (please use some kind of sorting aid, so you know exactly, which valve and spring is for which cylinder !!). Before you start, make a short list of components you will propably need, so you will get some impression about the total cost. Ron is right with the heads, but I will only know the German hourly rates in a workshop (the only workshop here 20 kms away for British Classics, and it´s not an exclusive one, charges 114,00 EUR plus tax :confused:, so I do everything on my own). For heads you should go to a an overhaul workshop for engines, they work much faster and checking heads or the rest of an engine is their daily work. Even if you do most of work here on your own you need them for cleaning, checking the surface if it´s even and give them a skim finish for the head gaskets. Only Cleaning and "soft skim" here is about 100 EUR for one 4-cyl head, I paid 350 EUR for both heads, but they had to take off 0,6 mm from the heads.
To take off valve springs is easy, a cheap spring compressor is all you need or you know someone with it.
For valve clearance in the guides you need the inspection from the specialized guys. Valve cleaning is easy. If seats are okay, valve grinding is easy also. Springs I bought new, it was cheaper than a spring rate test.
 
Thanks again guys.

I've asked for quotes to refurb the heads, and even looking at refurbed ones to price up.

Have run into a slight pickle though, is there anything I'm missing when going to remove the inlet manifold? Removed the 6 bolts either side, plus the hoses I can see, but the thing won't budge. I'm also unsure as to how I remove the throttle link??(bit that heads toward cabin from carbs) looks like that needs to be disconnected too.
Is it just stuck on after all these years or am I missing something big?

Thanks,

Mick
 
Hi Mick,

You will see a cylindrical nylon coupling, typically they are white, but I have seen black ones also. Remove the split pin closest to the engine, thus disconnecting the throttle linkage. You'll also need to disconnect the downshift cable (if automatic) and the fuel lines. With all the bolts removed, it should in theory now lift off, but theory does not always equal reality :rolleyes:

Ron.
 
Afternoon all,

Thanks for the descriptions, I've managed to get everything off that I need to, but the manifold is still pretty stuck. Judging by the amount of silicone or sealant built up around the edges, it seems like the previous owner was pretty liberal during application. Slowly working my way around with a Stanley knife removing that and trying to go as deep into the cracks as possible, but still not budging.

How much force can I apply when trying to pry the manifold off? I'm just a bit worried about cracking or warping the aluminium. Is there a particular spot that would work best?
 
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