| Author | Message | ||
     Joshua Smith (98hoo) New Member Username: 98hoo Post Number: 28 Registered: 09-2002 |
What are the symptoms of sticking valves? Do they occur all the time, just when the engine is under strain, at high speeds???? I am trying to diagnose a problem I have had for 3 + years, and I thought this might be the answer. Thanks in advance for the help | ||
| J E Robison Service Co (Robisonservice) Member Username: Robisonservice Post Number: 57 Registered: 10-2002 |
The symptoms are: 1 - intermittent staggering of the engine, usually at highway speeds and often in hot weather 2 - random misfire and specific misfire fault codes There is an article on this subject on my web site in the LR service area. I describe a test you can do to see if you have the problem. John www.robisonservice.com | ||
| Jason T. Barker (Speedminded) Member Username: Speedminded Post Number: 182 Registered: 10-2002 |
Ticking upon startup, sometimes clears up within a few seconds but eventually it won't go away. I think it has something to do with carbon buildup. I would suggest using an oil that contains ingredients that will dissolve/clean the buildup. Upon switching to Mobil 1 Synthetic after the 1st oil change when I bought my Disco (now has over 120k miles) the ticking was reduced almost completely. I don't know if Mobil I actually contains ingredients to help reduce buildup but it did run alot smoother. A couple oil changes (10k miles later) the ticking became more pronounced, especially on startup. A couple weeks ago I drained a little oil and added a half quart of Gunk engine cleaner/treatment (yeah, I know...I'm not a fan of power in the bottle crap either). I started it back up (still ticking), ran it for a couple minutes, then checked the oil level. I added the rest of the engine cleaner in and when I started it back up there was absolutely no tick. The directions says not to drive the vehicle with the cleaner in...just to run it for a certain period of time and then change the oil. The disco has been parked since then (putting 19k mile transmission and T-case in this weekend) so I haven't ran/driven it since so hopefully it sitting in there will clean it out completely before I change the oil tomorrow. | ||
| Joshua Smith (98hoo) New Member Username: 98hoo Post Number: 29 Registered: 09-2002 |
Thank you for your link. Unfortunately, it sounds just like what I have. Codes always read #8 cylinder misfire, and I have already changed the VSS. I guess I better start saving my pennies. | ||
| Eddie (Honu) Member Username: Honu Post Number: 66 Registered: 01-2003 |
get a product called seafoam. run a bottle through yoursystem, maybe two. that should clean up the problem. i had the same exact symptoms on my 95 disco. someone on this reccomended the stuff about a year ago to me. i get it at napa. cheers.. its similar to total system cleaner | ||
| Paul Long (Humveewannabe) New Member Username: Humveewannabe Post Number: 17 Registered: 03-2003 |
I also find to get the Sea Foam to the back cylinders, (Mine has misfire on 7, sometimes 8 during decell at hiway speed) you may need to slip a small length of vinyl tubing into the intake manifold. On a DII the only vacuum ports leading into the intake manifold are at the very front of the engine. By letting it suck the fluid out of the bottle at idle, not much gets to the back cylinders. It cleans the front ones up good. Exhaust valves are tough since whatever hits them has burned. Sea Foam when test burned in the metal container cap leaves an oil residue after the volatile ingredients are burned off. That may be what loosens the carbon on the valve stem, but the carbon I've run into on valves with a wire wheel can be about as hard a the metal itself, so maybe it just lubes up the situation.?. It does make a difference if the problem is not severe. Mine was so bad, I had to pull the plugs, wet the cylinder up with Sea Foam (available in spray form, works very good for penetrating fluid and carb cleaner but doesn't evaporate overnight) crank a little without starting, spray more, crank, until I was sure the exhaust valve was wet with the stuff. Let stand overnight, or the longer the better. Run it hard when you start it. It got me 20,000 miles, but is starting again. I've been thinking of pressurizing the cylinder with air, removing the spring and seal, and chucking the valve stem in a drill. By spinning and reaming it for awhile (dry) maybe it would open up the guide or wear the junk off the valve at least. I'm going to experiment with mine before replacing valves, since the problem is likely to come back. (perhaps if someone knows the oversize reamer to use on the guides, it wouldn't come back) Since I don't think valve grinding compound would get in there, and it would be hard to get it out without possibly wearing out valve seal or over wearing stem and guide.... My next idea; I use a "liquid burnisher" on sensitive contact points of heating equipment and circuit boards. (burnish is to rub without cutting) So maybe by spinning it and trying to get that fluid down the stem, it would clean it up. Nothing like good old carbon tet.... Things were easy back then. I'm showing my age. And my hands havn't fallen off. Yet. | ||
| Greg French (Gregfrench) Senior Member Username: Gregfrench Post Number: 318 Registered: 11-2002 |
Mine had similar problems...codes for misfires all over the place...engine staggering...thought it might be valves. Just for the heck of it, I put Magnecore wires in. It stopped all of my problems. It cleared my check engine light, I have more power, no hesitations. What a difference it made. You might want to try that before a valve job and see if it helps. | ||
| Grant Lawson (Grant) Member Username: Grant Post Number: 56 Registered: 01-2003 |
John at Robison Service!!! thanks for the link and the info,!What a gentleman!! | ||
| Dean Chrismon (Chrismonda) Member Username: Chrismonda Post Number: 91 Registered: 12-2002 |
Had the same problem. I cost a little over 2 grand. You will know if you have a stuck valve. No power | ||
| Jorge Verdeflor (Jrolfedrev) New Member Username: Jrolfedrev Post Number: 2 Registered: 02-2003 |
I do have a intermittent ticking too with check engine light and I consulted to one of the trusted Rover Tech and he recommended a Valve job (basically rebuild the valve) with total cost of less than 2k in SoCal. I need to check if it's a loose heat shield. What is the sypmtoms for a valve job? Can someone explain a valve job? |
