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I went on a trip of around 350km last weekend and about half way (after staying the night/camping), I noticed that the engine was making tappet tapping noises under acceleration.

Scenario: drove 150km on highway(100-110kph), then 5km on corrugation limestone road to camp site (30-50kph) and then came out again (and returned) to go shops later on that night and noticed nothing out of the ordinary.

Next day: Limestone road (70 - 90kph) then once on bitumen the ticking was noticeable when applying throttle.

Also: Engine was low on oil, 5mm under the rough part on dipstick, filled up in the morning before continuing, approx 2L was added.

Visited a fellow forum member who noted that the car was smoking when taking off, but I have only noticed smoke on one occasion since then.

Specs:

1978 C210 Skyline 4 door

L24 motor-Stock Internals

Manual Transmission

V8 LX torana radiator

The tappets are audible when idling at 650rpm, which is all normal for this car.

What should I do?

I have spoken to a mechanic friend and he suggested that we take the top end apart and check all the oil galleries and rockers/tappets.

Is this a good idea first off?

Last but not least am I overreacting?

thanks for any input.

Edited by Socrates
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...What should I do?

I have spoken to a mechanic friend and he suggested that we take the top end apart and check all the oil galleries and rockers/tappets.

Is this a good idea first off?

Hi,

I'd start by investigating where the oil went...

How many kms has the engine done?

When was the oil level last checked?  Serviced regularly? Correct oil?

Are there obvious oil leaks from the engine? Oil filter seal OK?

Any oil film on the back of the car, above the exhaust?

Ask your mechanic friend to do a compression check.

Next step - adjust tappets

Last but not least am I overreacting?

Always a possibility...

Good luck - hopefully some real mechanics will chime in soon.

JH

Whip the rocker cover off and have a look for anything suspicious, and check your clearances with a feeler gauge. It's not a horrible job.

My car was a bit down on power a fortnight ago, and a little noisier, and when I pulled the cover off I found that the rocker arms for no 6 had come off completely and were just bouncing around loose. I put them back on and the car is going much better, unsurprisingly.

Hi,

I'd start by investigating where the oil went...

How many kms has the engine done? 157,000km

When was the oil level last checked?I don't recall checking oil at least 2 weeks before trip, and oil could have slowly gone as blowby.  

Serviced regularly? Serviced in January 2010 and June 09 before that was Jan 2006, the car never used to get used and was always sitting.

Correct oil? Yes

Are there obvious oil leaks from the engine? No

Oil filter seal OK? Yes

Any oil film on the back of the car, above the exhaust? I have 1 3/4" turndown tip, so it doesn't go near the body unfortunately. However it does make the ground black if it sits there idling.

Ask your mechanic friend to do a compression check.

Next step - adjust tappets How difficult?, Can mechanic friend do this?

Always a possibility...

Good luck - hopefully some real mechanics will chime in soon.

JH

Whip the rocker cover off and have a look for anything suspicious, and check your clearances with a feeler gauge. It's not a horrible job.

If I take the rocker cover off does that mean I have to get a new O-ring seal for it?

Just happen to have a Gregory's manual for 78/80 Skylines. Here's some info for your mechanic: Valve clearances:

Inlet: 0.20mm (cold), 0.25mm (hot)

Exhaust: 0.25mm (cold), 0.30mm (hot)

It says to "measure clearances between camshaft and rocker arm and NOT between the rocker arm and valve stem".

You might need a new gasket if the old one is damaged.

JH

http://zdriver.com/forums/showthread.php?t...ht=valve+adjust

and this one (better)

http://www.atlanticz.ca/zclub/techtips/valveadjust/

and step by step (the one I follow)

http://www.picturetrail.com/sfx/album/view/1803105

I have used genuine gasket for the cam cover, and it leaks if you dont use a film sealant on both sides (tiny tiny amount)

Just dont tighhten the cam cover bolts too much, as they will snap (like i did)

Of course he can adjust tappets, he's awesome!! I mean, yes I can :woot:

Socs, what do you mean it makes the ground go black?? If it's burning oil, then there's a bigger issue then just an oil leak. Which it does have, obviously.

Cheers for the info guys, I'm more of an RB25 kinda guy, don't know much ( or anything really) about the old school Skylines, except that their sick! Lol

I have a turndown tip exhaust, so the gasses come out towards the ground.

It makes a blackish spray mark on on the ground if its left idling for 10min or so.

I'm pretty sure its just carbon that's come out with water.

I have a turndown tip exhaust, so the gasses come out towards the ground.

It makes a blackish spray mark on on the ground if its left idling for 10min or so.

I'm pretty sure its just carbon that's come out with water.

if the smoke is black, its fuel (running rich)

if its white, its burning oil

there's no smoke when I've had it idling and looking at it, it just spits black droplets.

i wouldn't worry about that, most l series cars will do that, I have found that the Gasket on the Rocker cover can split at the back of the motor, Against the Firewall, i had that happen to me on a trip and it sprayed a fine film of oil over the firewall,

its an easy job to do, pull the cover off, clean both surfaces, and put some Blue gasket glue in the place of the original gasket, refit, easy as

Most newer - i.e. newer than a 240K, L Engines have a hollow cam - oil from the engine, pumped up by the oil pump is is fed into the camshaft through holes in the cam journals (the bits that old the camshaft in place). Oil is pumed into the cam, and squirts out holes to keep the whole valvetrain lubricated... the lumpy bits of the cam - the lobes - rub against the rocker arms that push the valves in and out to let fuel into the engine, and exhaust gasses out... On Datsun engines, one end of the rocker arm sits on top of the valve, and the other end sits on and adjustable post... on other engine, the post isn't adjustable, but is forced up by oil pressure, these are called Hydraulic Lifters - dajusting the tappets is done by adjusting the post so there is a very small gap between the back of the lobe of the camshaft and the rocker arm, as per the instructions from MAG86...

Here is what I would do - park the car in front of your neighbours house, take the rocker cover off, and start the engine... oil will squirt out of all of the little holes in the camshaft... go all over the engine, and all over the road outside your neighbours... what you are looking for is to make sure oil is coming out of ever hole... it should shoot about 20cm...

If the hole into the camshaft is blocked, no oil will come out of a bunch of holes... if no oil comes out of only one or two holes in different spots on the cam, just those two galleries are blocked... clear them with a bit of wire... if the oil is blocked, the cam is rubbing on the roker without any lube, it will be a bit noisey, and eventually wear through the hardening on the cam and the rocker... and without lube, it is of course noisey... low oil means low oil pressure, means the same problems... check the oil and keep it within range... if you put 2L in, that means the engine only had half the oil it is supposed to... that means the oil gets twice as hot, and is more runny, so makes things more noisey...

Once you have oil coming out of every hole, do the tappet gaps... If the tappet gaps are too big, the rocker is further way from the valve, when the camshoft pushes it down, instead of a 1mm 'runup' it has 2 or 3mm, so instead of a tap, it is a wack... hence the noise...

After adjusting the tappets. If you listen carefully, maybe by holding a screwdriver against the rocker cover when the engine is running, and against your ear you should be able to hear where the noise is coming from... I recommend holding the pointy and of the screwdriver against the engine, rather than your ear, but, up to you... if the noise is coming from the very front of the engine, it is probably your timing chain or cam wheel... if in the middle or other end, it is probably a noisey rocker that is a bit worn out, or the lobe of the camshaft is worn...

don't worry about the black on the floor, carbon is sticking to the wall of your exhaust, when the engine is running, some water is washing the carbon off the exhaust, and pushed through the exhaust onto the floor...

fill your oil, and see how much you use per 300km... if you are using more than about 1L per 1500km, you have a real problem that need to be fixed, probably new rings which is a big deal... less than that, just know your engine is getting a bit tired and will need a rebuild one day... if the car blows puffs of white smoke when you take off from the lights, or when you first start it, it is probably only the valve seals that need to be replaced... still a bigish job, but not as much as the whole engine rebuild...

Let us know how you go...

Daewoo

Edited by Daewoo

UPDATE: Took car to a recommended mechanic and he said that it was most probably an exhaust manifold leak, which is nowhere near the severity I was thinking of.

The story also checks out as NA Goodness knows, the cabin has a strong smell of fumes if one window is open.

The fix for this is new exhaust which I'm planning to get anyway. see here :C210 Exhaust.

However, your advice has not gone to waste as I will do the tappet adjustment and oil gallery check this weekend, pending on arrival of rocker cover seal from Nissan.

Also should I go genuine for seal or after-market? If so where should I call up?

Thanks for the help everyone

Edited by Socrates

I have my rocker cover off all the time, and never bother replacing the gasket. Until they tear they don't seem to leak. Repco do a cheapo (rubber?) gasket that'll do fine - and I bet it works out closer to 1/10th the cost of a genuine Nissan item.

As said, don't overtighten that sucker.

I'd probably just give your old one a little freshen up with some Hylomar (blue gasket spray) and not worry about replacing it unless it starts dribbling oil.

  • 4 years later...

Most newer - i.e. newer than a 240K, L Engines have a hollow cam - oil from the engine, pumped up by the oil pump is is fed into the camshaft through holes in the cam journals (the bits that old the camshaft in place). Oil is pumed into the cam, and squirts out holes to keep the whole valvetrain lubricated... the lumpy bits of the cam - the lobes - rub against the rocker arms that push the valves in and out to let fuel into the engine, and exhaust gasses out... On Datsun engines, one end of the rocker arm sits on top of the valve, and the other end sits on and adjustable post... on other engine, the post isn't adjustable, but is forced up by oil pressure, these are called Hydraulic Lifters - dajusting the tappets is done by adjusting the post so there is a very small gap between the back of the lobe of the camshaft and the rocker arm, as per the instructions from MAG86...

Here is what I would do - park the car in front of your neighbours house, take the rocker cover off, and start the engine... oil will squirt out of all of the little holes in the camshaft... go all over the engine, and all over the road outside your neighbours... what you are looking for is to make sure oil is coming out of ever hole... it should shoot about 20cm...

If the hole into the camshaft is blocked, no oil will come out of a bunch of holes... if no oil comes out of only one or two holes in different spots on the cam, just those two galleries are blocked... clear them with a bit of wire... if the oil is blocked, the cam is rubbing on the roker without any lube, it will be a bit noisey, and eventually wear through the hardening on the cam and the rocker... and without lube, it is of course noisey... low oil means low oil pressure, means the same problems... check the oil and keep it within range... if you put 2L in, that means the engine only had half the oil it is supposed to... that means the oil gets twice as hot, and is more runny, so makes things more noisey...

Once you have oil coming out of every hole, do the tappet gaps... If the tappet gaps are too big, the rocker is further way from the valve, when the camshoft pushes it down, instead of a 1mm 'runup' it has 2 or 3mm, so instead of a tap, it is a wack... hence the noise...

After adjusting the tappets. If you listen carefully, maybe by holding a screwdriver against the rocker cover when the engine is running, and against your ear you should be able to hear where the noise is coming from... I recommend holding the pointy and of the screwdriver against the engine, rather than your ear, but, up to you... if the noise is coming from the very front of the engine, it is probably your timing chain or cam wheel... if in the middle or other end, it is probably a noisey rocker that is a bit worn out, or the lobe of the camshaft is worn...

don't worry about the black on the floor, carbon is sticking to the wall of your exhaust, when the engine is running, some water is washing the carbon off the exhaust, and pushed through the exhaust onto the floor...

fill your oil, and see how much you use per 300km... if you are using more than about 1L per 1500km, you have a real problem that need to be fixed, probably new rings which is a big deal... less than that, just know your engine is getting a bit tired and will need a rebuild one day... if the car blows puffs of white smoke when you take off from the lights, or when you first start it, it is probably only the valve seals that need to be replaced... still a bigish job, but not as much as the whole engine rebuild...

Let us know how you go...

Daewoo

Sorry to hijack the thread.... but do you know how the oil feed is on a RB25DET... I have no oil inside the rocker covers?

Stephen

  • 2 weeks later...

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