Isuzu 4lc38

[RobinJ]

I have a keel tank cooled 4lc38. When the engine gets up to proper running temperature the oil pressure light will light at tickover or low revs.

This only started after an oil/filter change. I have since changed the oil again to higher(thicker) grade but the problem remains.

just to add the water temp is fine.

You didn't say how old the engine is?

There was no mention of whether you changed the filter and oil!

Have you checked for any leaks?

 

If the oil pressure switch had a problem, it would either stay on or not come on at all, only time I have had problems with oil lights going on and off was when something fell onto the switch!

 

If the filter is the screw on type, it is possible that the wrong type could interupt the flow, possibly true of cartridge types too?

 

Wrong type of oil will cause problems because of the viscosity at different temperatures, but there would have to be a major difference to lower pressures by a large amount (not familiar with API-CG, but up to CF I wouldn't think it wouldn't have such a big effect)!

 

What to do first? Depends on cost of oil compared to another filter I think!

If that doesn't change anything, you need to get some figures for the oil pressure and look at whether its the pressure relief valve, pump or something else? It will help if you know the pressure relief settings from the manual (usually in the 50psi area), also the routing of oil ways, so you know whether you are measuring before or after the relief valve!

[Denis R]

I had this issue once on my Beta - no problems at all until oil and filter change with an after market filter. Changing the filter for the OE version cured it and haven't had the problem since. It could be that the cross reference Fram - Mahle isn't correct and you're already one 'generation' removed with the Isuzu OE - Fram conversion....

The internals may be completely different - flow 'inside to outside', 'outside to inside', 'plugging' valve, no 'plugging' valve, the permutations are almost endless....

I'd try an OE filter first.

[Pretty Funked Up]

I stated on the off I did change both oil and filter. Then changed the oil again (not filter).

The engine panel is basic one with warning lights and alarm for oil and water.

I had teh water system all checked and the sender tested when i put new thermostat in, so water temp is fine.

 

Thank you so much for the link to the manuals Chris, only got chance to take a peak now but it looks perfect and i will be reading all that later on. GREAT FIND there. thanks.

 

getting oil and new filter at lunch time to do later as well

 

thanks again people for the help

[Pretty Funked Up]

Thanks for your help guys - i've think i've cracked it.

It was the filter, so far sp good, just need to take her for a couple of hours chug yet to really make sure.

thanks again for your help

[blackrose]

Thanks for your help guys - i've think i've cracked it.

It was the filter, so far sp good, just need to take her for a couple of hours chug yet to really make sure.

thanks again for your help

 

Was the filter blocked ot the wrong type?

[blackrose]

Try googling "Westerbeke" engines. They appear to be rebadged Isuzu engines and the workshop manual pdf on their website (free) was identical to the one for which I paid £30 ( ) with just the isuzu name missing.

 

Try this one - the drawings are identical to my Isuzu manual and should cover your engine as well I believe. There are some minor differences like alternator type but the engine bits appear to be the same.

click here

 

 

Chris

 

I have the Isuzu 55 (not the very latest one), and although some of the specs are the same it looks a bit different to the one pictured on the Westerbeke manual?

 

http://www.hmiengines.co.uk/User/Documents...t%20leaflet.pdf

[Pretty Funked Up]

The filter appears fine but it was made Mahle. I have gone back to Fram now (not sure who makes the OE but i doubt very much its isuzu).

 

In the manuals there are some differences but mostly cosmetic. the westerbeke are spot on for oil pressure sender etc etc.

 

Interestly enough i noticfed in the westerbake manuals is says...

"the use of CC or higher grade oil (eg CD) by well known manufacturers is recommended. The oil seleted should be used thereafter."

Edited November 11, 2008 by Pretty Funked Up

[chris w]

I have the Isuzu 55 (not the very latest one), and although some of the specs are the same it looks a bit different to the one pictured on the Westerbeke manual?

 

http://www.hmiengines.co.uk/User/Documents...t%20leaflet.pdf

The drawings in the Westerbeke book are identical to my Isuzu 35 workshop manual other than external things like exhaust, alternator etc. So the series of tappet adjustments, for example, are an exact copy of my set of drawings.

 

Chris

[Pretty Funked Up]

its definitely the filter

 

thanks for your help and the westerbeke info is great, saved loads of hassle with HMI.

 

tank u tank u

[chris w]

Now switch that bl**dy generator off...... it's after 8pm

 

PS: did you change the oil back to API-CC?

Edited November 11, 2008 by chris w

[Pretty Funked Up]

thanks chris. all info is greatly appreciated and used.

 

I dont run a genny as my isuzu purrs like a kitten and (given enough time) will do the job fine.

but the 8 rule will die just like the 70's throughbacks who enforce it

[chris w]

thanks chris. all info is greatly appreciated and used.

 

I dont run a genny as my isuzu purrs like a kitten and (given enough time) will do the job fine.

but the 8 rule will die just like the 70's throughbacks who enforce it

 

All very well...... but did you change back to API-CC oil?

[Pretty Funked Up]

Hi just a quick line in haste...

 

I couldnt affort both so was left with decision of which and i chose the filter as had only done the oil 2 weeks ago. I've made a mental note to get back to a CC or CD as soon as possible.

 

Did you see the bit in westerbeke manual about use of higher grades?

[chris w]

Hi just a quick line in haste...

 

I couldnt affort both so was left with decision of which and i chose the filter as had only done the oil 2 weeks ago. I've made a mental note to get back to a CC or CD as soon as possible.

 

Did you see the bit in westerbeke manual about use of higher grades?

Yes I did.... BUT in my Isuzu manual it expressly "forbids" the use of higher grades stating that it will have adverse effects on the engine; although it doesn't say what these might be in the manual. One of them I know, from conversation with HMI, is bore-glazing.

Edited November 12, 2008 by chris w

[Pretty Funked Up]

Those manuals are very useful to anyone with a isuzu, who is poor like me. free to download. great find, thanks dude.

 

reading between the lines of the manuals and the hmi advice it will be the changing of oil from lower grade to higher that causes the glaze? if you had CD etc. from the start it would be ok. just choose a grade and stick to it.

 

maybe i'm way off the mark there dont know.

[chris w]

Those manuals are very useful to anyone with a isuzu, who is poor like me. free to download. great find, thanks dude.

 

reading between the lines of the manuals and the hmi advice it will be the changing of oil from lower grade to higher that causes the glaze? if you had CD etc. from the start it would be ok. just choose a grade and stick to it.

 

maybe i'm way off the mark there dont know.

Yep you are I'm afraid. HMI's product specialist is a very nice guy by the name of Steve Lovegrove. He told me specifically ONLY to use CC grade with the exception that, in emergency, I could go to CD grade but no higher. The reason is that CC grade is a less refined (rougher) oil and it effectively helps scrape any glazing off the bores. At least that's how he described it - I'm not an oil expert.

 

Chris

[alan_fincher]

Yep you are I'm afraid. HMI's product specialist is a very nice guy by the name of Steve Lovegrove. He told me specifically ONLY to use CC grade with the exception that, in emergency, I could go to CD grade but no higher. The reason is that CC grade is a less refined (rougher) oil and it effectively helps scrape any glazing off the bores. At least that's how he described it - I'm not an oil expert.

 

Chris

And this is definitely not just an HMI Isuzu thing, it's pretty widespread advice for other engine makes too.

 

The specially formulated Lister Petter Oil is also an API-CC. They are not doing that to save money, as these older oils are blended in such small quantities. It's because that's what experience shows the engine requires.

 

You are unlikely to knacker it by running with an API-CG for one oil change interval, but it's definitely not recommended, and if the engine were under warranty definitely to be avoided.

[andy1]

mahle filters are original equipment ,they make the filters for most manufacturers and rebadge them . rgds andy

[Pretty Funked Up]

thanks guys, i am definitely going to change to CC soon as i can.

 

interesting what andy says about mahle. maybe i got given the wrong model

Edited November 13, 2008 by Pretty Funked Up

[rover220]

£15 gets you 5 litres of isuzu/hmi api-cc oil. the sooner you can get some api-cc in the better really.

[Denis R]

Mahle are an OEM supplier to most of the major European manufacturers, original fit for Isuzu in the Far East is probably Denso.

There's nothing sub-standard about Mahle, I reckon the cross reference was wrong and you ended up with a filter with the wrong characteristics.

[andy1]

Mahle are an OEM supplier to most of the major European manufacturers, original fit for Isuzu in the Far East is probably Denso.

There's nothing sub-standard about Mahle, I reckon the cross reference was wrong and you ended up with a filter with the wrong characteristics.

they have a factory in japan aswell , rgds andy

[Pretty Funked Up]

Hi again

 

OK I tried to start the new year off well and did the oil change. Went off to nearest marina which has loads of oil, must of been 15-20 different types, searched through them all and 15w40 cc was nowhere to be seen. All the 15w40 where cg grade or higher.

There was 1 called Supreme20 which stated cc grade, 2 more - SAE30 and SEA40 which didnt state an API grade, and finally (the one i bought) 20w50 API-CC.

Pumped out the oil, took out the pressure sender and cleaned it all up (was a tad gunky), popped that back in and filled her up to just over 3\4 upto max level.

 

All seems fine and dandy so far with pressure (3.5hrs).

 

HMI recommend 15w40 API-CC, will i be ok with 20w50 API-CC?

 

 

PS. I used HMI own branded oil on the first change when all the problems started.

Edited January 2, 2009 by Pretty Funked Up

[lazyboy]

Isuzu oil was supplied in bulk by Texaco under their brand name "Ursatex" 15w40 API-cc. When that became to expensive from texaco the supplier was changed to Rock Oil who supply isuzu with their equivelant 15w40 api-cc brand.