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> Jensen Healey & Jensen GT Tech > Engine & Transmission > problem hot starts & milky oil on dipstick |
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> Jensen Healey & Jensen GT Tech > Engine & Transmission > problem hot starts & milky oil on dipstick |
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| problem hot starts & milky oil on dipstick | Rating: 
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| Posted: 11-15-2008 06:01 pm |
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1st Post |
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ozzadavies Member 
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hi there, some advice please for a novice mechanic. I've had my JH for 6 months or so and have noticed that hot starts are getting more difficult. The plugs foul up (I've had the dellortos tuned) and there's some white sludge on the dipstick when I check the oil level. Once the engine starts it behaves very well with a smooth tickover. I'm so hoping that this isn't going to be expensive to fix...thanks in advance
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| Posted: 11-16-2008 02:27 am |
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2nd Post |
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RossB Member 
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Hi Ollie, Others may have better information for you, but in my experience white sludge in the oil means there is water in there - and that is not good. I have little experience with Lotus 907 engine so I do not know the most likely source of the water. I don't have any suggestions about the hot starting problem. I hope it all turns out well. Cheers, Ross.
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| Posted: 11-16-2008 11:09 pm |
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3rd Post |
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ozzadavies Member
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Hi Ross, thanks for the advice. You're probably right, it's not a good thing. I checked today and noticed that sludge is coming out of the breather pipe into the air filter chamber too. Perhaps a head gasket problem?
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| Posted: 11-17-2008 01:01 am |
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4th Post |
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Jensen Healey Super Moderator 
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Open the oil filler cap and look inside the cam cover. Then open the drain plug and see what comes out. If it's got any mayonaise in it you should not run the engine until it's fixed. If the oil is clean, you may have condensation from not running the engine up to full temprature. Some people start the engine several times a year for a few minutes and think they are "keeping it running". Bringing it up to full temp evaporates any condensation and fuel that may find it's way into the oil. Good luck, Kurt
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| Posted: 11-17-2008 08:34 pm |
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5th Post |
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Jon Plowe Member
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Before the doom and gloom congratulations on owning a JH, the're a great car as demonstrated by the taking of a class this year in the HSCC Championship http://www.hscc.org.uk/ and me getting a class win last year and a 2nd this year in the HSA Championship http://www.hillclimbandsprint.co.uk/ Oil in the water is never good news and certainly hints at a head gasket problem. Not a very difficult or necessarily expensive job - it's the '....while I'm at it I might as well do this, etc' that bumps the job up. Certainly needs sorting asap or it could get pricey. Apart from warped heads and dodgy liners I've had problems with head gaskets with (wider) rubber sealing rings around the head oil feed hole as opposed to types with a (narrower) copper ring. The amount of metal around the oil feed hole in the top of the block is not great and if the edges have been knocked of by corrosion and the gasket locating dowels are not working as they should then the gasket can be out enough to cause sealing problems.
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| Posted: 02-02-2009 01:51 pm |
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6th Post |
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ozzadavies Member
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Seems like a happy outcome to this saga. I had a couple of checks made to the engine that indicated nothing was wrong. First test was a radiator pressure test that checked to see whether the coolant pressure changed when the engine was being revved - negative. The other was a radiator gas test to see whether any gas was getting into the coolant from the engine - again negative. The engineer's advice to me was to flush the engine and drive it more. It seems like the milky oil was appearing due to atmospheric conditions, i.e. more moisture in the atmosphere. Plus, my hot starts have improved. I replaced the old air filter with K&Ns which means that the breather pipes from the crank case and cam cover are no longer routed into the air filter chamber. As my engine is a 'heavy breather' it used to discharge muck into the chamber. My theory is that it also discharged gas into the chamber that was stopping ignition from happening when I tried to start the car from hot. Has anyone else had experience of this?
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| Posted: 02-03-2009 04:07 am |
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7th Post |
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Sylva Member
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Oil in the water can come from two places, the engine cooling fluid (the radiator) or condensation. If it is from the cooling system then you will need to add water, so before you do anything including panic, run the engine, check the cooling level, is it constant? if it is then you probably have condensation. Kelvin
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| Posted: 02-03-2009 01:19 pm |
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8th Post |
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Jensenman Member
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White or yellowish stuff on the dipstick indicates condensation. That's usually a result of poor crankcase ventilation which the 907 is known for. About the only way to correct that is to rework the crankcase breather system to add a PCV (Positive Crankcase Ventilation) valve instead of the 'passive' OE system. One day I'll do that to mine and see how it works out. Or, just make sure the oil gets changed on a regular basis. If it's got a brown 'chocolate milk' look, that's not a good sign; that's emulsified oil/coolant/water mixed and is generally a sign of a leaky head gasket or other inter. A car that starts good cold but gas fouls plugs (dry fluffy black deposits, oil fouling is shiny black) and has hard hot restarts generally is getting excessive fuel. The easiest way to check: on the hot restart, if it doesn't start immediately push the throttle about halfway (do NOT pump it!) and hold it at that point while starting. If it starts much easier, it pretty much has to be excessive fuel. I'd start by making sure the Dellorto 'chokes' are all the way closed. A too-high 'wet fuel level' (float level too high) can cause this as well.
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| Posted: 02-03-2009 02:50 pm |
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9th Post |
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colinw59 Member 
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On 15851 I ran a hose from the rear crankcase vent to the rear of the K&N filters, split via a T connector. I also fitted a PCV valve enhancer, or filter, (located on Ebay) in-line. Having ran it with this in place last year, I was not suprised to how much gunk this filter picks up. It has a drained plastic bowl that enables you to see exactly what's not making its way into the carbs. These are currrently listed on Ebay. http://cgi.ebay.com/ebaymotors/MG-B-TF-ZR-ZS-ZT-MGT-RV8-Fuel-Saver-PCV-HHO-HOD_W0QQitemZ390028451027QQihZ026QQcategoryZ46097QQssPageNameZWDVWQQrdZ1QQcmdZViewItem Attachment: pcv.jpg (Downloaded 287 times)
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| Posted: 03-09-2009 02:58 pm |
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10th Post |
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ozzadavies Member
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Well confused now. I fitted a PCV valve as suggested (thanks Colin) and, even on short trips it fills with clear clean water. It's coming from the radiator as I keep having to top it up. Hot starts are great now, engine runs great otherwise.
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| Posted: 03-09-2009 03:15 pm |
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11th Post |
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colinw59 Member
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If the water is clear, then it must be finding its way into the engie via condensation. Assuming it's not atmospheric, water vapor inside the engine would suggest a bad head gasket or maybe a crack in the water jacket. Any white smoke from the exhaust? Let's pray for the former! FYI I'm a Brit living in the USA. I grew up in Brighton and crossed the pond in 1992. I get back once a year to see family & friends. Good luck, Colin
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| Posted: 03-09-2009 10:56 pm |
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12th Post |
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Brett Gibson JH5 20497 Member
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How about a Brit living in Rochester New York, came in 65. Thats probably why I've had so many LBC. Brett
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| Posted: 03-22-2009 08:37 pm |
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13th Post |
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ozzadavies Member
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Nice to see some fellow Brits, and thanks for the advice Colin. Next time you make it over and have a spare couple of hours let me know... I took the car into a great Lotus specialist (Morland & Jones in Hammersmith) to get the problem checked over. I got there, bonnet up, and was explaining the problem when I noticed the dipstick was totally covered in emulsion. First time I'd seen that. Turns out it was a head gasket problem that they fixed along with de-coking the head, resetting the valve clearances (quite out apparently), and changing the timing belt, tension bearing and plugs. The PCV valve was pressurising the crank case by the way. I took out the inner white plastic thingy on it today and those plastic beads so that it's now just a catch pot. All great and fab and all that. Engine is much more responsive at lower revs, seems much more perky, obviously no water or gunk anymore. But...now a new problem seems to have emerged. Over about 3000 revs the engine hesitates and misfires. Could it be mixture too lean perhaps, or an electrical fault like the coil or distributor arm?
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| Posted: 03-25-2009 02:58 pm |
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14th Post |
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Brett Gibson JH5 20497 Member
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Rule of thumb Oz is "make the ignition timing electricals correct before touching the carbs". Unless of course you see an obvious problem with them. You did say they changed your timing belt so I would assume the timing was reset, and your plugs were changed, what are your wires like and how old, points / rotor / cap, any loose wires around the coil / dist.. And whats this white PCV your talking about, dont believe I have seen one on a JH before, is your car fitted with emmisions ??? If you think your ignition is fine then I would put a draught tester over the inlet of each carb barrel and see what kind of air draw each is pulling, if thats way off then you you get then fun of tuning your carbs. Good luck. Brett
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| Posted: 04-14-2009 12:07 pm |
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15th Post |
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ozzadavies Member
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Hi Brett, the PCV is as Colin's JPEG above. I fitted one as a catch pot from the breather pipes. I hven't got any emmissions equipment as far as I know (the car was supplied new in California but imported to England in 1990). The dodgy misfiring was cured by fitting a new condenser and cleaning up the rotor arm tip - thanks for the guidance. It's now running very well. I am concerned though that I'm getting a lot of water in the catch pot with a bit of oil mixed in. I have to empty it frequently - every 50 miles or so. The oil on the dipstick and filler cap are fine - no residue at all. The head gasket has been replaced (see my post above) so could there be something god-awful wrong like a crack in the block? Many thanks, Ollie
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| Posted: 04-14-2009 05:17 pm |
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16th Post |
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Brett Gibson JH5 20497 Member
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Ozz, I dont think you have a water issue, I believe what you are seeing, due to your trapping it, is just plain old condensation that a engine normally produces, along with a touch of oil vapor, short trips were the engine doesnt really heat up creates more condensation, and cold weather, were as if you drove it so it became hot thru out, and a warmer climate, that heat would burn off the cond. Personally, I would do without the trap myself and just run the breather under the car, out of sight out of mind. Trapping it means you have to maintain the trap. just my two cents. Brett
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| Posted: 06-03-2009 05:42 am |
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17th Post |
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edward_davis Member 
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I don't want to start a new thread because my concern fits into this one, I think. I, too, had been finding emulsion on my dipstick, as well as oil leaking around the oil filler cap, both signs of breather problems as I understood them. When I pulled the breather hoses off, set up for my K&N filters by the PO, they were all full of the mayo-like oil emulsion as well. I thought that they'd just gotten full of gunk, stopped up, and caused the other breather problems. Not so simple. Once I got the hoses off that connect directly to the crankcase and the oil filler, I discovered the PO had wedged little pieces of kitchen scrubber sponge into the hoses. Presumably, when I bought the car in 2005, they were relatively clean bits o' sponge, and had let some of the crankcase gasses through, but by now they were completely clogged with oil gunk. I think those bits of sponge were the main cause of my breather problems: too much pressure in the crankcase, and when the oil tried to escape, either through the dipstick tube or around these sponges, it created that milky emulsion. Yuck. So, two questions: 1) should I be worried about running my JH with the sponges removed from the oil breather? 2) why did the PO put said sponges into the pipes in the first place? My wife pointed out that the PO last drove the car while it still had to meet CA smog rules, so the alteration of the breather system might have been related to passing a smog inspection. That's the best explanation we've been able to come up with. Thanks, Edward
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| Posted: 06-03-2009 10:15 am |
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18th Post |
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ozzadavies Member
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Hi Edward, sorry to hear about your problems, they sound very similar to mine. Presumably the sponges were a misguided effort to stem the flow of crap coming out without stopping the gas/air escaping from the crankcase. Or to mask the problem whilst selling. I'm guessing, but I think that excessive crankcase pressure will kill your bottom end and cause piston rings to give up. I had a painful experience with mine, spending a small fortune getting the head gasket replaced and the head de-coked by a Lotus specialist only to have to spend a larger fortune replacing the engine after the bottom end went a month later! I'm not really a mechanic so I had a pretty steep learning curve trying to work out what was going on. I don't know whether the symptoms I originally saw (gunk in the air box causing non-starting) were down to the head or the bottom end, or indeed both. Or whether fixing the head and the subsequent enthusiastic driving forays around London was too much for the bottom end. Good luck with it, I hope you find a resolution
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| Posted: 06-04-2009 07:18 am |
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19th Post |
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subwoofer Member
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I bet you are eager to get the car back out on the road again, Oliver? Miss Jensen has been sitting in the garage without moving an inch for the last month, and the solution is the same as for you - a "new" engine. I decided to call it quits when the coolant became contaminated with oil and was forced into the overflow reservoir, the airbox has had mayo in it for the last year... Mine hasn't let go yet, so it will be interesting to tear it down over the winter to see what kind of condition my condition is in. -- Joachim
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