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Need help please.


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Hi everyone. Before I get started I know next to nothing about motors. My dad was a mechanic, but do to circumstances, he no longer has his sight and has to tell me how to do everything. I have a 97' Esprit. Been having a lot of diffuculties with it. Two shops have told me that the compression is way to low, while the third said that there was no way the compression was low. The third shop said that a car like this may need to have a wet test done for the compression. I have the tool to do a compression check that my dad can tell me how to use. MY QUESTION RIGHT NOW IS, DO I NEED TO DO A WET TEST OR DRY? I do not know exactly what that means, my dad does however and will be able to help me.  

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Hi,

I think I'm correct in saying that you normally do a dry compression test first & if any of the results are low then you repeat the test with a squirt of oil in cylinder via the spark plug hole before you do it, if the reading improves it is the rings that are worn ( as the oil has helped to seal the worn rings ) if it's the same it's more likely to be the valves that are at fault.

Regards, Phil.

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A compression test is done by getting the engine to normal operating temperature, then removing all the plugs. Fit the compression tester to one cylinder, apply full throttle (ideally with the ignition disabled...undo the lead from the distributor to the ignition....the low tension connection, not the HT lead to the distributor cap) and then crank the engine over on the starter for about 10 rotations...then read the gauge to see what the maximum compression pressure was. Then repeat the procedure for the other cylinders. Note down the readings for each cylinder. They should be close to the "book" figure and within 10% of each other

 

That's a "dry" test. If the results are low, the next thing is to repeat the test after squirting some oil into each cylinder beforehand. Hence "wet" test. This will help seal the rings to the bores....if the compression pressures are now better and OK compared with the "book" figure, then the rings are not sealing properly and that must be addressed. If there is no change, then the valves are leaking on their seats and the loss of compression pressure must be rectified by removing the head and recutting/regrinding the valve to valve seat fits.

 

You should get yourself a copy of the "Servicing Notes"....they are expensive, but essential. Also, if you become a Full Forum Member, you get access to the parts list ...and that's also extremely useful and comprehensive. I would doubt that any of the "shops" you have taken the car to wil have any idea of what the compression pressure of this car should be... the Servicing Notes will tell you...or someone on here will know! My knowledge doesn't go far past the early 4 pot turbos, where the pressure is 130 lb psi for the low compression engine such as mine.

Scientists investigate that which already is; Engineers create that which has never been." - Albert Einstein

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Remember that the compression spec can vary from the spec listed in the book, which is at sea level.  if you are higher than altitude, then your acceptable compression limit will lower by the same percentage as the air density at your altitude varies from sea level.

Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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That is the specification for the Esprit V8 engine (918 Twin Turbo V8). which had a compression ratio of 8.0:1.  Unless the engine had been changed in a way that changed the compression ratio, then that is the specification for the minimum cylinder pressure (at sea level).

 

If you live above sea level then your min compression will be lower.  For instance I live at 5300 ft, so my air pressure is lower at about 12psi, vs 14.7psi for sea level, so the minimum compression pressure for the same engine at my altitude would be ~18% lower or about 127psi.

 

So where do you live?

 

The Lotus manual actually gives a tolerance for that 155psi of +/- 15psi... which is confusing since it gives that as a "minimum" compression pressure.  Usually a minimum is a one sided tolerance

Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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Well I actually live at 4960 elevation. So my minimum compression will be between yours and sea level. Definitely closer to yours. I do not have an owners manual, as the person that we got the car from did not have it. I am strongly considering becoming a full member of this site, so that I have the standard specs for the car. Being only 400 ft in difference from you though, would I be safe to assume that getting it to 128-130 psi would be a good compression for the vehicle?

 

Hopefully tomorrow I will be able to put up those numbers for a dry and wet compression check. I do not think that I was lied to, by two different shops, about the same thing, when I did not tell either of them what the other said. I do believe that they don't know what the actual compression should be, but one of them had said that some of the numbers were 50% off. Like 127 and 70, I believe I heard as low as 47. That was a dry test so if they were telling the truth then the vehicle would definitely be way out of range.


One more note. I was there for the second compression test. After looking over what you said earlier I realized that the engine was not at normal operating temp. You said that it needs to be at normal temp. I assume that even though it was cold, with those numbers, that would still mean a compression issue?

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Normal operating temp just means the engine has been run & has been warmed up in the last 20 mins or so.  To be honest if you see >100 on all cylinders with a cold engine then compression will be OK & not the cause of noticeable issues.

 

When doing the test, make sure you have a fully charged battery.  If the engine spins over slowly there is more time for the air to leak out and compression will drop.

 

As above, make sure also the throttle is open  - if the engine can not suck air in properly there will not be enough to compress.  This is often a mistake where the engine has electronic throttle control that people in the trade who should better make.

 

BTW you mention problems with the car - what are they (misfire, lack of power etc) & when do they occur (hot,cold, first starting etc)

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Okay thanks. I had a battery issue. Fixed that two nights ago. The main problem is the car starts hard, real hard, cold. And if it is run to normal temp. And turned off it won't start for at least 20 min. Not even from a jump. If it is around 60 on the temp. gauge it starts fine.

Okay thanks. I had a battery issue. Fixed that two nights ago. The main problem is the car starts hard, real hard, cold. And if it is run to normal temp. And turned off it won't start for at least 20 min. Not even from a jump. If it is around 60 on the temp. gauge it starts fine.

I will not be able to do the readings today. Something has come up. I am also going to sign up for full membership tonight after work. Cause it says my posts are limited without it. I also need those manuals and parts list.

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Doesn't sound like a compression issue. I would still check it.. but the main things I would be interested in is your engine coolant temp sensor, your MAP sensor and your cam timing -- My best guess is it Sounds like your intake cam on the right side (passengers side) has skipped a tooth or has slipped the timing. This cam is the "reference" cam and is how the engine determines if its on ignition stroke or intake stroke. Now.. when you do your compression test, if you get a different reading from the right bank as from the left bank.. it becomes more probable that your intake cam is off.

Modifying esprit's.. now that's fun..

PS... I AM NOT A CERTIFIED MECHANIC.. I Have chosen to help those in need, in the past and must not be construed as being a certified technician.

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As above & does the MIL / engine warning light come one (& if not does it work - ie come on when you first switch on the ignition for a few seconds).

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I will definitely check that. Unfortunately the thing that came up yesterday landed the car in a shop for a quick hose fix. I hope. One of the clutch lines on the car went when we took it out for a test run after dumping some fluid in it. I think it was engine repair. My dad's idea. I did not think that it would help but he was convinced it would. She seemed to start a little better. As I said though a clutch line went out and I was really mad. So I am having a shop put a new one on. Wish I could have them do the engine stuff but it seems like every place in my area has no idea how to work on European cars. So as soon as we get her back in a few days I will be doing the test and I will definitely check that right side compared to the left side.


Yes the engine light is on.

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Leaking injectors? 

Vanya Stanisavljevic '91 Esprit SE | '97 XK8

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Hey guys I am looking for a clutch line right now. I was in the shop on this website and I found all sorts of stuff for carbon fiber and brakes and exhaust but no clutch lines. I typed clutch in the search and zero results appeared. Am I doing something wrong? The line that comes right off of the container where the brake fluid goes was made of a hard plastic and split in one spot (see picture). Was that line supposed to be metal? The guy at the shopped asked me to find out because it is the only plastic line on the clutch system, the rest being metal. He does not want to put a plastic line on if it should be metal and I would agree on this.

 

 

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post-17260-0-84516400-1399616384.jpg

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Awesome. Since I also have a 97' v8 I will assume it is the right one. Any idea how I get ahold of a new one. Or do they come in most auto stores? Like I said earlier this is the first car I have really actually tried to learn anything on and I am just starting out so I do not know much.

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Lots of people, including myself, have replaced the red clutch hydraulic pipe on their Esprits, either because of this issue or to avoid it. Do a search and I'm sure lots of threads will pop up. Most people seem to replace with a braided one rather than replace like for like. SJ's PNM SW Lotus Cente will all sell you a replacement hose, and it took me, as a below average ability spanner monkey, about 2 hours to replace. I'd guess someone near you could make you a replacement braided hose with the correct end fittings rather that you buy one from the UK

Normally Aspirated - and lovin' it!

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Contact JAE they will probably have the plastic hose, but a braided metal hose is available too!

Vanya Stanisavljevic '91 Esprit SE | '97 XK8

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Awesome. Anyone have a phone number? I have spoken with eight different places in my area and surrounding area and none of them will touch it. This is one of the reasons I have to start doing it myself. I have a guy who knows how to work on vehicles like this but he does not have the tools to crimp any hoses or lines. I will be needing to order the part as is in that case.

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I would not spend any time / money on engine diagnostics, compression tests etc until you have read out the fault codes that have caused the engine warning light to come on.

 

Almost any workshop will have a scan tool / code reader and should charge $40 or less.  If you prefer DIY then a cheap code reader should work (I dont have a V8, but 1996 cars on should all support OBDII although Lotus may have been a bit late to the party - can a V8 owner confirm the cars have a standard connector?). 

 

Things like http://www.ebay.com/itm/U480-OBD2-OBDII-CAN-BUS-Code-Reader-Engine-Scanner-Auto-Car-Diagnostic-Interface-/121057639043?hash=item1c2f98fa83&item=121057639043&pt=Motors_Automotive_Tools&vxp=mtr should suit if you dont want to use a laptop.   This requires a laptop with bluetooth but there is lots of software available http://www.ebay.com/itm/ELM327-Bluetooth-OBD2-OBDII-CAN-BUS-Interface-Auto-Diagnostic-Scanner-Scan-Tool-/250939390393?hash=item3a6d2739b9&item=250939390393&pt=Motors_Automotive_Tools&vxp=mtr

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