Aloha.
My wife and I are the new 2nd owner of a beautiful 98 disco. It has 60k and the original owner had the car in Oklahoma most its life and according to the carfax, took it in to rover annually.
It's a great vehicle. Just what we like. It has great style and comfort and fits the bill for a 4wd my wife requires for her new job in September.
We paid not much for the vehicle 2 days ago. Drove it like crazy even before we bought it. Now, I've started to hear a tick in the motor at idle that goes away on the freeway. OMG!
I wanted to take it right back to the 'mechanic' that sold it to me and get my money back but I didn't. He said the original owner was his buddy and just shipped the vehicle 6mos ago to hawaii where we are and it runs great....aside from an occasional ticking noise. Carfax backed this story to the T.
After reading up in several forums, I'm deciding NOT to try and return the D1 to the mechanic. I want to turn this truck into the reliable high maintenance high mile beauty this forum makes possible. The motor seems easy to get to all over and there's only a relatively short list of major problems this engine has and plenty support from the likes of Disco Mike and Spike555 and others. If there was no forum, I would dump the truck. Instead, I'm gonna scour this forum and share MY journey with this forum only to keep me going like so many others.

My fist question is obvious.

How do I get rid of this ticking sound??

Mahalo

 

You a'int gonna like this.

The "tick" that is not there cold, but comes on warmed up, and goes away at faster speeds is usually a cylinder liner that has broken loose due to chronic or intense overheating. It hits the head gasket. As piston speed increases, it can't reverse as fast as the piston, so eventually an rpm is reached where it not longer contacts and ticks, but it is still moving.

One way to fix is pin the liner, search forum for posts about that.

One way is to buy a rebuilt engine block with "top hat" style flanged liners.

Sometimes the tick only happenns at a higher temp. You can remove the thermostat that is there, and install a $10 180F model.

Ticks can also be valve train components, a cracked oil pump, and one guy even found a wrench left inside the engine by a mechanic. You can take a yard stick, hold one side to your ear, and touch various spots on the engine and "hear' what is going on inside, like valve covers, area below water pump, etc.

Some people drive with the tick for a really long time.

Now, if you are having head gasket or cracked block (behind that liner) then usually you will have a sound like water bubbles rushing under the dash. Might be air to be purged from system, might be exhaust gas in coolant, there is a $50 test for that.

You'll want to download the RAVE service manual set.

 

Thanks Savanna Buzz

Your post responses are always most helpful. Your keeping discos alive!

I thought so about the liner.
I ordered the 180 thermostat and want to open up the valve covers and oil pan to see oil sludge condition. I also ordered a mechanical oil pressure and water temp guage and a code reader.
When I do open this motor up, is there a way to ID the liner that is slipping without taking the heads off too?
Is there a liner number that is most prone to slipping if I wanted to pin just the prone ones?
And also, how would I 'reset' a slipped liner up against the head gasket before I pin it? I wouldn't want to heat it and bang it upwards from under the car....I think. Unless of course there's a known trick out there for this.

Thank you Savanna Buzz!

 

May not be the liner, could be PS pump, oil pump (cracks), valve train, etc. There have been posts this week about pinning liners.

 

I did see the write up with pictures and a parts order. Would stainless bolts be better than the alloy because of the aluminum block? I know stainless is a more brittle than regular steel so it may be a compromise?

If it is something else like a water pump or oil pump, I can tackle that too if the pinning doesn't work or my too be installed gauges tell me pressure is low or temp too high.

 

Before you start worrying about a slipped liner know that this is less common for D1s. If it were a slipped liner you won't most probably notice a change in drivability of the vehicle. If nothing changed don't worry too bad. I noticed on mine that when I park it on a upslope it seems to made a 'ticking' sound right after starting but then quickly subsided once I got back to level ground. Oil level was down a bit and after a quick oil change, no more sound regardless of incline.

 

Thanks you guys.
i've been scouring this forum like crazy. Disco people are great. i love this truck more now because of the forum personalities. Savanna Buzz, you've helped so many by your replies.

There are many opinions on whats best for the flushing of the motor of sludge. Disco Mike says hardcore ATF flush while spike555 says no way try ATF; its a myth.

So my question is this:

Who do I listen too, Disco Mike or Spike555?

 

my tick was the rocker arm tip was broken off cost me about $12 + shipping to fix it, was the last one at the rear of the engine passenger side, no noise cold then it would sound like a sewing machine super annoying

as far as engine flush, atf, stp, sea foam, marvel mystery oil, theres about 20 ways I can think of off the top of my head, I have seen guys put a pint of kero or diesel fuel in run it for 20 minutes and drain do I recommend it probly not, try to find a way that a lot of guys can attest to working for them, in the end it is always up to you the owner since you have to live with the results good or bad

btw welcome to the forum, with your disco being from Oklahoma you may be lucky to have a rather rust free one

 

thanks Tom R

Ill order the plenum gaskets and stuff so i can get to those valve covers. My knocking is for sure coming from drivers side rear of the engine. It is like a sewing machine sound.

well yesterday, since Im waiting for my thermostat gasket for the 180 thermostat and filter sandwich for the oil gauge i ordered online(i live in hawaii), I decided to try a bottle of CD2 in the crank case. I did nothing for the knock. Im disappointed but not discouraged at all. Just had to try it. Ill stop there and not try an ATF flush or kerosene.

My oil pan gasket came in the mail so I can now drop the pan to see stuff from that angle.
The rave instructions mentions a LRT-12-183 tool to reinstall the sump. Ill try to do it without such tool cause im so eager to see inside the motor. Ill take some pictures and post them here later today. Ill close it all up and refill with rotella 15-40.


Does anyone know how to ID a slipping liner from the open sump? and if so, whats the technique to push it up toward the head manually before I pin it?

Aloha!

 

if it sounds like a sewing machine you may simply have a broken rocker tip like I did, while the oil pan is off check to make sure the oil pickup bolts are tight, I recall reading posts from guys that their oil pickup was loose

you may want to print out sections of the rave manual and you will need to convert the torque specs from newtons to foot pounds unless you have a newton torque wrench, a lot of things have to be torqued on this engine