|
|
| Welcome to the Mercedes 190 forum Welcome to the Mercedes 190 owners forum, the place to be for all owners and lovers of the Mercedes 190E, 190 and 190D cars. Including Cosworth (2.3 16v and 2.5 16v), EVO 1 and EVO 2 models. Modified and concourse, track cars and daily drivers, all are welcome. This free UK based club was started back in November 2005 to serve the w201 community and now has over 4000 members from all around the world and 340,000 + posts. The members welcome you and encourage you to stay a while and have a look around. We offer you friendly chat and access to some very useful information as well as tutorials with photos and videos for many common repair and maintenance jobs. Whatever your needs there is a good chance you will be able to find what your looking for. Such as our Mercedes 190 buyers guide Sign up to gain access to all areas including for sale / classified areas and country wide meetings and events. Many forum features and sections are only available once you sign up. Join our us at mercedes190.co.uk! If you're already a member please log in to your account: |
| W201 Compression figures | |
|---|---|
| Topic Started: Tue Mar 17, 2009 7:35 pm (642 Views) | |
| Johnboy Mac | Tue Mar 17, 2009 7:35 pm Post #1 |
Member
  ![]](http://209.85.122.89/static/1/pip_r.png)
|
Diesels 2.0 & 2.5, compression ratio 22:1, new value 26-32bar, wear limit 18bar approx. Petrol 1.8, 2.0, 2.6 compression ratio between 9:1 & 9.2:1, new value 10-12bar, wear limit 8.5bar approx. 2.3-16 compression ratio 10.5:1, new value 14-16bar, wear limit 12.5 approx. 2.5-16 compression ratio 9.7:1, new value 12-14bar, wear limit 10.5 approx. Note: Diesel max. permissible differences between individual cylinders 3.0bar. Petrol max. permissible differences between individual cylinders 1.5bar. (1 bar = 14.5 psi) |
 |
 
|
| merc190uk | Tue Mar 17, 2009 9:12 pm Post #2 |
Steve
|
Nice one thanks pinned  |
|
|
|
| Johnboy Mac | Wed Mar 18, 2009 1:17 am Post #3 |
|
Member
|
No probs. I think worth having, it's not the be all & end of an engines condition but it's simple & cheap why to diagnoise a poss. fault. |
|
|
|
| RobertE | Wed Mar 18, 2009 7:05 am Post #4 |
Serial victim...
|
Excellent, Johnboy. And reassuring! I did the compressions on the new 2.5 the other day and got a very close average of 190 psi across the piece. The others are a tad lower (Bertha at 180 and Brunhilde at 170) but the highest mileage car has the highest compressions! |
|
|
|
| Johnboy Mac | Wed Mar 18, 2009 5:08 pm Post #5 |
|
Member
|
Robert, it's stange that as I don't know any technical reason for it compaired to the lower mileage cars all things being equal. You may recall I did mine @ 170k or something around that and got an average of 177psi (12.2bar) just hope it stay that way until I put funds aside for a rebuild. |
|
|
|
| RobertE | Wed Mar 18, 2009 5:51 pm Post #6 |
|
Serial victim...
|
Yes, I know what you mean, mate - the bottom ends are clearly hugely strong, which is why they worked so well in competition, but the top end is always going to make me nervous; stories of cracked valves, etc., will wake me up at 3 a.m.! But really, I think they are utterly magnificent cars and worth starting a 'sinking fund' for. But I'm pleased about the compressions - I'm organising a leakdown test next week so that I can ask the right questions of the engine (s). |
|
|
|
| manalishi | Fri Apr 3, 2009 10:13 am Post #7 |
|
Member
|
Yikes! Guys, is it possible to have compressions of 75 | 95 | 95 | 92 psi in a 2.3-16 and for the engine to work? (hoping that Matt's equipment is misreading...!) |
|
|
|
| jeremy | Fri Apr 3, 2009 10:19 am Post #8 |
Member
|
Yikes , one is clearly down isn't it.? But having said that , think what it will be like once it's been attended to.  Plenty of time to put it right. Jeremy  
|
|
|
|
| manalishi | Fri Apr 3, 2009 10:24 am Post #9 |
|
Member
|
Um... I was expecting figures closer to 180-190psi! Or am I doing something stupid with the 1bar=14.5psi maths? |
|
|
|
| Will | Fri Apr 3, 2009 10:39 am Post #10 |
Member
|
Yes, it's certainly possible for it to have those compression readings and run still. It would probably be difficult to start from cold, low on torque and mid range power though would probably feel more 'healthy' at high RPMs. If it's not smoking like a trooper it almost certainly wants a head rebuild. Will |
|
|
|
| RobertE | Fri Apr 3, 2009 10:47 am Post #11 |
|
Serial victim...
|
No, the arithmetic is right. Important to test on a warm/hot engine, though, and certainly worth using some sort of additive - Redex - Wynns - STP, whatever. You'll do no harm and if you have sticky piston rings or fouled-up valves it can only help. |
|
|
|
| manalishi | Fri Apr 3, 2009 12:34 pm Post #12 |
|
Member
|
Seems the numbers aren't a mis-read, so the next step is that leakdown test. I gather from a search of old postings that it'll identify whether there's a big bill, or a HUGE bill in the offing... |
|
|
|
| cossie connoisseur | Fri Apr 3, 2009 12:42 pm Post #13 |
fat tits
|
yes your car will run but will is right regarding how it will run one thing to add will be the the engine will vobrate a fair bit and you really wont be getting 100% out of her so if you drive one that is 100% then you will see and feel quite a difference. tbh the costs can vary but the norm is up to £2000 for a rebuild so make sure the car is serviced regular to make it last and save up for a rebuild. it nearly always the top end and very rarely the bottom end un less your really bad with servicing |
|
|
|
| Matt | Fri Apr 3, 2009 12:47 pm Post #14 |
Administrator - Hawk Eye
|
Yes, im tending to think valve/s may be the issue here. I shall do a leakdown test on it to confirm. |
|
|
|
| cossie connoisseur | Fri Apr 3, 2009 12:57 pm Post #15 |
|
fat tits
|
carbonising on the valvles will be the likely one |
|
|
|
| Will | Fri Apr 3, 2009 1:49 pm Post #16 |
|
Member
|
And incorrect valve clearance. Bet the exhaust ones are tight! Will |
|
|
|
| manalishi | Fri Apr 3, 2009 2:07 pm Post #17 |
|
Member
|
Will - you may remember that I thought it was underwhelming to drive, so what you say above goes with that. Being an auto, it was harder to keep up in the top of the rev band, and there was a definite sense that - at low to moderate revs - it had no more 'go' in it than the 2.0 I used to have. |
|
|
|
| Johnboy Mac | Fri Apr 3, 2009 4:36 pm Post #18 |
|
Member
|
Manalishi, if the engine ain't using much oil it fair to assume it's top end fault but that's a very rough guess.A leak down test should high light the actual fault. |
|
|
|
| Will | Sat Apr 4, 2009 4:04 pm Post #19 |
|
Member
|
Hi Barry, Yep, it all ties in with classic compression/top end issues  You do really need to sit down though and work out where you stand with this car - what you want out of it, what you're willing to spend on it etc. A top end overhaul can get quite expensive depending on the condition of the head/valves, what needs doing etc. A few cracked valves, and/or damaged/worn valve guides, plus the cost of parts (gaskets, bolts, seals etc) and the machining costs (skimming if needed, decoking, fitting the guides, lapping in the valves etc) Maybe (ideally) a new timing chain/tensioner too (would be criminal not to on a 2.3 unless it's very recent/new) If you're paying for all of this to be done, I'd say you could be looking at anywhere between £1000-2000. Will |
|
|
|
| manalishi | Mon Apr 6, 2009 11:03 am Post #20 |
|
Member
|
Will - Yes, after we have the results from the leakdown test, Matt and I have to have a long look at the £££ figures. With other jobs needing doing, too, it's looking a bit 50:50. Which is a shame after all the recent efforts on it. Johnboy-IRL - I didn't run the car for long enough to know if it uses oil. I sent it to Matt pretty quickly after being underwhelmed by the driving experience. |
|
|
|
| Johnboy Mac | Mon Apr 6, 2009 1:26 pm Post #21 |
|
Member
|
Manalishi, all the signs of top end rebuild required rather than anything wrong with bottom end, hope all works out o.k. |
|
|
|
| cosser | Tue Nov 24, 2009 2:56 pm Post #22 |
|
Member
|
Hi Guys n Gals, I got the compression tested a couple of months ago and I had approx Cyl 1; 180 Cyl 2; 90 Cyl 3; 180 Cyl 4; 180 I've just bought an Am tech tester off ebay to do a wet test on number 2 to tell me if its rings or valves and I decided to test them all m first.To my confusion i got C1=4Bar C2=0Bar C3=4Bar C4= 3.8Bar...????? I did a wet test on Number 2 and that crept up to 2 Bar which was what I was expecting but I'm stumped as to why these readings are so low...?? Could all of my rings (or worse) have gone bad so quickly,especially as I am rarely driving her since I found out about Cyl 2 in June,and even then I'm drivin like a priest..lol..!! I warmed the car to 80 C unplugged the Green Ignition wire and took out the Fuel relay,and did each test with all of the plugs out.Am I doing something wrong...??? The weird thing is that the ratio between the cylinders is more or less the same in relation to the original test (Cyl 1,3,4 even and Cyl 2 down)...????? Any Suggestions ....??? Cosser..!! |
|
|
|
| RobertE | Tue Nov 24, 2009 3:04 pm Post #23 |
|
Serial victim...
|
Redex! I don't know which car you have, (I'm assuming it's a valver) but 3 out of four are very respectable, so don't panic. (You're obviously not). I'm starting to realise how much cr*p can build up and the effect that this can have on simple things like valve guides and seats. |
|
|
|
| Martrider | Yesterday, 10:57 AM Post #24 |
Longest build time in history?
|
Comma Detox i have found to make a huge difference on my 2.0ltr when used once a year. It's about £14.99 or £19.99 but works very very well in my experience. Get it at Hellfreuds. I had a friend who i trust implicitly who worked for Comma - you couldn't believe a word she said about the products as she was a model dressed in lycra - but she did work for them for 5 years! lol |
|
|
|
| RobertE | Yesterday, 11:22 AM Post #25 |
|
Serial victim...
|
There has been much talk of running Diesel engine oil for 5-600 miles before flushing it out and refilling with 'normal' oil. I know the M100 lads do this - it's something to do with detergents |
|
|
|
| Johnboy Mac | Yesterday, 12:57 PM Post #26 |
|
Member
|
I think I've mentioned this here before. ATF is a great engine cleaner, drop the old oil and refill with ATF. Let run for 20/30mins at idle with the odd rev to 2000 only. |
|
|
|
| cosser | Yesterday, 3:45 PM Post #27 |
|
Member
|
Thanks for the Advice guys, I did post this problem in its own space in the Engine section under" strange compression test results" or something like it..lol...!! Could you guys have a look at that post if you could and give me osome feedback...it would be much appreciated..!!.. Thanks Again. Cosser..!! |
|
|
|
| 1 user reading this topic (1 Guest and 0 Anonymous) | |
| « Previous Topic · Engine · Next Topic » |
3:36 AM Nov 26
